Fix Android Resolver unable to resolve mainTemplate.gradle in Unity 2022.2+ or 2023.1+ (#547)

Later version of Unity (2022.2+ or 2023.1+) changed the way to specify
Android Gradle plugin version. As a result, `AndroidGradlePluginVersion`
getter would fail to find the version and Android Resolver would fail
when `mainTemplate.gradle` is in use.

This fix searches Android Gradle plugin version using two regex to
ensure Android Resolver can find the version in any Unity version.

Also fixed the reflection exception because Unity added a new version of SetApplicationIdentifier() in 2021

Author: chkuang-g

source/AndroidResolver/src/PlayServicesResolver.cs

@@ -571,8 +571,17 @@ public static string GradleVersion {
         // Gradle plugin version.
         private static DateTime mainTemplateLastWriteTime = default(DateTime);
         // Extracts an Android Gradle Plugin version number from the contents of a *.gradle file.
+        // This should work for Unity 2022.1 and below.
+        // Ex.
+        //   classpath 'com.android.tools.build:gradle:4.0.1'
+        private static Regex androidGradlePluginVersionExtract_legacy = new Regex(
+            @"['""]com\.android\.tools\.build:gradle:([^'""]+)['""]$");
+        // Extracts an Android Gradle Plugin version number from the contents of a *.gradle file for
+        // Unity 2022.2+ or 2023.1+.
+        // Ex.
+        //   id 'com.android.application' version '7.1.2' apply false
         private static Regex androidGradlePluginVersionExtract = new Regex(
-            @"['""]com\.android\.tools\.build:gradle:([^']+)['""]$");
+            @"['""]com\.android\.application['""] version ['""]([^'""]+)['""]");
 
         /// <summary>
         /// Get the Android Gradle Plugin version used by Unity.
@@ -609,7 +618,12 @@ public static string AndroidGradlePluginVersion {
                                                                 SearchOption.TopDirectoryOnly));
                     foreach (var path in gradleTemplates) {
                         foreach (var line in File.ReadAllLines(path)) {
-                            var match = androidGradlePluginVersionExtract.Match(line);
+                            var match = androidGradlePluginVersionExtract_legacy.Match(line);
+                            if (match != null && match.Success) {
+                                androidGradlePluginVersion = match.Result("$1");
+                                break;
+                            }
+                            match = androidGradlePluginVersionExtract.Match(line);
                             if (match != null && match.Success) {
                                 androidGradlePluginVersion = match.Result("$1");
                                 break;

source/AndroidResolver/src/UnityCompat.cs

@@ -64,8 +64,8 @@ private static int VersionFromAndroidSDKVersionsEnum(object enumValue, string fa
             //Fall back on auto if the enum value is not parsable
             return -1;
         }
-        
-        // If the enumName is empty then enumValue was not represented in the enum, 
+
+        // If the enumName is empty then enumValue was not represented in the enum,
         // most likely because Unity has not yet added the new version,
         // fall back on the raw enumValue
         if (String.IsNullOrEmpty(enumName)) return (int)enumValue;
@@ -462,7 +462,9 @@ private static string GetUnity56AndAboveApplicationIdentifier(BuildTarget buildT
     private static bool SetUnity56AndAboveApplicationIdentifier(BuildTarget buildTarget,
                                                                 string applicationIdentifier) {
         var setApplicationIdentifierMethod =
-            typeof(UnityEditor.PlayerSettings).GetMethod("SetApplicationIdentifier");
+            typeof(UnityEditor.PlayerSettings).GetMethod(
+                "SetApplicationIdentifier",
+                new[]{typeof(BuildTargetGroup), typeof(string)});
         if (setApplicationIdentifierMethod == null) return false;
         var buildTargetGroup = ConvertBuildTargetToBuildTargetGroup(buildTarget);
         if (buildTargetGroup == BuildTargetGroup.Unknown) return false;

source/AndroidResolver/test/src/AndroidResolverIntegrationTests.cs

@@ -484,10 +484,24 @@ private static void ValidateAndroidTargetSelected(
                 });
             IntegrationTester.Runner.LogSummaryAndExit();
         }
+
+        // Verify if PlayServicesResolver properties are working properly.
+        var testCaseResult = new IntegrationTester.TestCaseResult(testCase);
+
+        if (String.IsNullOrEmpty(PlayServicesResolver.AndroidGradlePluginVersion)) {
+            testCaseResult.ErrorMessages.Add(String.Format(
+                "PlayServicesResolver.AndroidGradlePluginVersion is empty or null"));
+        }
+
+        if (String.IsNullOrEmpty(PlayServicesResolver.GradleVersion)) {
+            testCaseResult.ErrorMessages.Add(String.Format(
+                "PlayServicesResolver.GradleVersion is empty or null"));
+        }
+
         // Also, set the internal Gradle version to a deterministic version number.  This controls
         // how gradle template snippets are generated by GradleTemplateResolver.
         PlayServicesResolver.GradleVersion = "2.14";
-        testCaseComplete(new IntegrationTester.TestCaseResult(testCase));
+        testCaseComplete(testCaseResult);
     }
 
     /// <summary>