Allow setting Gradle properties in project.xml (#1859)

* allow setting gradle jvmargs in project.xml

* Make gradle.properties fully configurable from project.xml.

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Co-authored-by: Joseph Cloutier <player3.14@gmail.com>

Author: giuppe

templates/android/template/gradle.properties

@@ -29,4 +29,6 @@ KEY_STORE=::KEY_STORE::
 KEY_STORE_PASSWORD=::KEY_STORE_PASSWORD::
 KEY_STORE_ALIAS=::KEY_STORE_ALIAS::
 KEY_STORE_ALIAS_PASSWORD=::KEY_STORE_ALIAS_PASSWORD::
-::end::
+::end::
+::foreach ANDROID_GRADLE_PROPERTIES::::if ((value != null) && (value != ""))::::key::=::value::
+::end::::end::

tools/platforms/AndroidPlatform.hx

@@ -485,6 +485,7 @@ class AndroidPlatform extends PlatformTarget
 		context.ANDROID_GRADLE_PLUGIN = project.config.getString("android.gradle-plugin", "8.7.3");
 		context.ANDROID_USE_ANDROIDX = project.config.getString("android.useAndroidX", "true");
 		context.ANDROID_ENABLE_JETIFIER = project.config.getString("android.enableJetifier", "false");
+		context.ANDROID_GRADLE_PROPERTIES = project.config.getKeyValueArray("android.gradle-properties");
 		context.ANDROID_DISPLAY_CUTOUT = project.config.getString("android.layoutInDisplayCutoutMode", "default");
 
 		context.ANDROID_APPLICATION = project.config.getKeyValueArray("android.application", {