Android: Add `isGame` application attribute, default to true

It can be turned off in the export preset with `package/classify_as_game`.

Upstream definition: https://developer.android.com/guide/topics/manifest/application-element#isGame

> `android:isGame`
>
> Whether or not the application is a game. The system may group together
> applications classifed as games or display them separately from other
> applications.

Also fixes replacing `android:allowBackup` in custom builds.

(cherry picked from commit 40a594c6ea1803279360fdfe725d507420cd68ec)

platform/android/export/export.cpp

@@ -903,6 +903,7 @@ class EditorExportPlatformAndroid : public EditorExportPlatform {
 		bool focus_awareness = p_preset->get("xr_features/focus_awareness");
 
 		bool backup_allowed = p_preset->get("user_data_backup/allow");
+		bool classify_as_game = p_preset->get("package/classify_as_game");
 
 		Vector<String> perms;
 		// Write permissions into the perms variable.
@@ -1006,6 +1007,10 @@ class EditorExportPlatformAndroid : public EditorExportPlatform {
 							encode_uint32(backup_allowed, &p_manifest.write[iofs + 16]);
 						}
 
+						if (tname == "application" && attrname == "isGame") {
+							encode_uint32(classify_as_game, &p_manifest.write[iofs + 16]);
+						}
+
 						if (tname == "instrumentation" && attrname == "targetPackage") {
 							string_table.write[attr_value] = get_package_name(package_name);
 						}
@@ -1758,6 +1763,7 @@ public:
 		r_options->push_back(ExportOption(PropertyInfo(Variant::STRING, "package/unique_name", PROPERTY_HINT_PLACEHOLDER_TEXT, "ext.domain.name"), "org.godotengine.$genname"));
 		r_options->push_back(ExportOption(PropertyInfo(Variant::STRING, "package/name", PROPERTY_HINT_PLACEHOLDER_TEXT, "Game Name [default if blank]"), ""));
 		r_options->push_back(ExportOption(PropertyInfo(Variant::BOOL, "package/signed"), true));
+		r_options->push_back(ExportOption(PropertyInfo(Variant::BOOL, "package/classify_as_game"), true));
 
 		r_options->push_back(ExportOption(PropertyInfo(Variant::STRING, launcher_icon_option, PROPERTY_HINT_FILE, "*.png"), ""));
 		r_options->push_back(ExportOption(PropertyInfo(Variant::STRING, launcher_adaptive_icon_foreground_option, PROPERTY_HINT_FILE, "*.png"), ""));

platform/android/export/gradle_export_util.h

@@ -263,12 +263,14 @@ String _get_application_tag(const Ref<EditorExportPreset> &p_preset, bool p_has_
 	bool uses_xr = (int)(p_preset->get("xr_features/xr_mode")) == 1;
 	String manifest_application_text = vformat(
 			"    <application android:label=\"@string/godot_project_name_string\"\n"
-			"        android:allowBackup=\"%s\" tools:ignore=\"GoogleAppIndexingWarning\"\n"
-			"        tools:replace=\"android:requestLegacyExternalStorage\" "
+			"        android:allowBackup=\"%s\"\n"
+			"        android:icon=\"@mipmap/icon\"\n"
+			"        android:isGame=\"%s\"\n"
 			"        android:requestLegacyExternalStorage=\"%s\"\n"
-			"        android:icon=\"@mipmap/icon\">\n\n"
-			"        <meta-data tools:node=\"remove\" android:name=\"xr_mode_metadata_name\" />\n",
+			"        tools:replace=\"android:allowBackup,android:isGame,android:requestLegacyExternalStorage\"\n"
+			"        tools:ignore=\"GoogleAppIndexingWarning\">\n\n",
 			bool_to_string(p_preset->get("user_data_backup/allow")),
+			bool_to_string(p_preset->get("package/classify_as_game")),
 			bool_to_string(p_has_storage_permission));
 
 	if (uses_xr) {

platform/android/java/app/AndroidManifest.xml

@@ -28,7 +28,7 @@
     <!-- If you want to add tags manually, do before it. -->
     <!-- WARNING: This should stay on a single line until the parsing code is improved. See GH-32414. -->
     <!-- TODO: Remove the 'requestLegacyExternalStorage' attribute when https://github.com/godotengine/godot/issues/38913 is resolved -->
-    <application android:label="@string/godot_project_name_string" android:allowBackup="false" tools:ignore="GoogleAppIndexingWarning" android:requestLegacyExternalStorage="false" android:icon="@mipmap/icon" >
+    <application android:label="@string/godot_project_name_string" android:allowBackup="false" android:icon="@mipmap/icon" android:isGame="true" android:requestLegacyExternalStorage="false" tools:ignore="GoogleAppIndexingWarning" >
 
         <!-- Records the version of the Godot editor used for building -->
         <meta-data