Add support for Google Services gradle plugin

The Google Services gradle plugin[1] helps enable use of Google services
in Android apps. Since this requires a `google-services.json` file to be
copied into the build directory, it needs to be a separate option in
addition to enabling the plugin in the `build.gradle` file.

1. https://developers.google.com/android/guides/google-services-plugin

Author: dbnicholson

doc/source/buildoptions.rst

@@ -91,6 +91,9 @@ options (this list may not be exhaustive):
 - ``--add-source``: Add a source directory to the app's Java code.
 - ``--no-compile-pyo``: Do not optimise .py files to .pyo.
 - ``--enable-androidx``: Enable AndroidX support library.
+- ``--enable-google-services``: Enable the Google Services Gradle plugin.
+  This option requires a ``google-services.json`` file in root of the
+  project directory.
 
 
 webview
@@ -152,6 +155,9 @@ ready.
 - ``add-source``: Add a source directory to the app's Java code.
 - ``--port``: The port on localhost that the WebView will
   access. Defaults to 5000.
+- ``--enable-google-services``: Enable the Google Services Gradle plugin.
+  This option requires a ``google-services.json`` file in root of the
+  project directory.
 
 
 service_library
@@ -177,6 +183,9 @@ systems and frameworks.
 - ``--add-jar``: The path to a .jar file to include in the APK. To
   include multiple jar files, pass this argument multiple times.
 - ``add-source``: Add a source directory to the app's Java code.
+- ``--enable-google-services``: Enable the Google Services Gradle plugin.
+  This option requires a ``google-services.json`` file in root of the
+  project directory.
 
 
 Requirements blacklist (APK size optimization)

pythonforandroid/bootstraps/common/build/build.py

@@ -548,6 +548,9 @@ def make_package(args):
     if args.fileprovider_paths:
         shutil.copy(args.fileprovider_paths, join(res_dir, "xml/file_paths.xml"))
 
+    if args.enable_google_services:
+        shutil.copy('google-services.json', 'src/main/google-services.json')
+
     # gradle build templates
     render(
         'build.tmpl.gradle',
@@ -864,6 +867,12 @@ def parse_args_and_make_package(args=None):
     ap.add_argument('--activity-class-name', dest='activity_class_name', default=DEFAULT_PYTHON_ACTIVITY_JAVA_CLASS,
                     help='The full java class name of the main activity')
 
+    ap.add_argument('--enable-google-services', dest='enable_google_services',
+                    action='store_true',
+                    help=('Enable the Google Services Gradle plugin. '
+                          'This requires a google-services.json in the root '
+                          'of the project.'))
+
     # Put together arguments, and add those from .p4a config file:
     if args is None:
         args = sys.argv[1:]
@@ -949,6 +958,12 @@ def _read_configuration():
               '--launcher (SDL2 bootstrap only)' +
               'to have something to launch inside the .apk!')
         sys.exit(1)
+
+    if args.enable_google_services and not exists('google-services.json'):
+        print('You must provide a google-services.json file for '
+              '--enable-google-services')
+        sys.exit(1)
+
     make_package(args)
 
     return args

pythonforandroid/bootstraps/common/build/templates/build.tmpl.gradle

@@ -6,6 +6,9 @@ buildscript {
     }
     dependencies {
         classpath 'com.android.tools.build:gradle:7.1.2'
+        {% if args.enable_google_services %}
+        classpath 'com.google.gms:google-services:4.3.14'
+        {% endif %}
     }
 }
 
@@ -27,6 +30,9 @@ apply plugin: 'com.android.library'
 {% else %}
 apply plugin: 'com.android.application'
 {% endif %}
+{% if args.enable_google_services %}
+apply plugin: 'com.google.gms.google-services'
+{% endif %}
 
 android {
     compileSdkVersion {{ android_api }}