[android]: Enable Firebase Crashlytics only for Beta builds

- Enable Google Mobile Services for all flavors except fdroid.
- Enable Google Firebase Services for all beta builds flavors fdroid
  only if google-services.json exists

We want to get all stars in εxodus privacy report.

Signed-off-by: Roman Tsisyk <roman@tsisyk.com>

android/build.gradle

@@ -5,19 +5,42 @@ buildscript {
     jcenter()
   }
 
-  ext.googleServiceEnabled = file('google-services.json').exists()
-  if (googleServiceEnabled) {
-    println("Building with Google Services")
-  } else {
-    println("Building without Google Services")
-  }
+  //
+  // The magic below is needed to disable Google Mobile Services (a.k.a GMS) and
+  // Google Firebase Services during the build time. Unfortunately, the only way
+  // to disable Gradle plugins is to add these hardcore switches to buildscript().
+  //
+
+  // Detect flavors from the task name.
+  def isFdroid = getGradle().getStartParameter().getTaskRequests().toString().toLowerCase().contains("fdroid");
+  def isBeta = getGradle().getStartParameter().getTaskRequests().toString().toLowerCase().contains("beta");
+
+  // Enable Google Mobile Services for all flavors except fdroid.
+  def googleMobileServicesDefault = !isFdroid;
+  // Add a parameter to force GMS.
+  ext.googleMobileServicesEnabled = project.hasProperty('gms') ?: googleMobileServicesDefault;
+
+  // Enable Firebase for all beta flavors except fdroid only if google-services.json exists.
+  def googleFirebaseServicesDefault = isBeta && !isFdroid && file('google-services.json').exists();
+  // Add a parameter to force Firebase.
+  ext.googleFirebaseServicesEnabled = project.hasProperty('firebase') ?: googleFirebaseServicesDefault;
 
   dependencies {
     classpath 'com.android.tools.build:gradle:4.1.2'
-    if (googleServiceEnabled) {
+
+    if (googleMobileServicesEnabled) {
+      println("Building with Google Mobile Services")
       classpath 'com.google.gms:google-services:4.3.5'
+    } else {
+      println("Building without Google Services")
+    }
+
+    if (googleFirebaseServicesEnabled) {
+      println("Building with Google Firebase Services")
       classpath 'com.google.firebase:firebase-crashlytics-gradle:2.5.1'
       classpath 'com.google.firebase:firebase-appdistribution-gradle:2.1.0'
+    } else {
+      println("Building without Google Firebase Services")
     }
   }
 }
@@ -45,8 +68,10 @@ repositories {
 
 apply plugin: 'com.android.application'
 apply from: 'secure.properties'
-if (googleServiceEnabled) {
+if (googleMobileServicesEnabled) {
   apply plugin: 'com.google.gms.google-services'
+}
+if (googleFirebaseServicesEnabled) {
   apply plugin: 'com.google.firebase.crashlytics'
   apply plugin: 'com.google.firebase.appdistribution'
 }
@@ -57,10 +82,13 @@ dependencies {
 
   implementation 'androidx.multidex:multidex:' + propMultiDexVersion
 
-  // Google Services
-  if (googleServiceEnabled) {
+  // Google Mobile Services
+  if (googleMobileServicesEnabled) {
     implementation 'com.google.android.gms:play-services-location:17.0.0'
-    implementation 'com.google.firebase:firebase-analytics:17.4.4'
+  }
+
+  // Google Firebase Services
+  if (googleFirebaseServicesEnabled) {
     implementation 'com.google.firebase:firebase-crashlytics:17.1.1'
     implementation 'com.google.firebase:firebase-crashlytics-ndk:17.1.1'
   }
@@ -227,10 +255,15 @@ android {
     manifest.srcFile 'AndroidManifest.xml'
     res.srcDirs = ['res']
     java.srcDirs = ['src']
-    if (googleServiceEnabled) {
-      java.srcDirs += 'flavors/google-services-enabled'
+    if (googleMobileServicesEnabled) {
+      java.srcDirs += 'flavors/gms-enabled'
     } else {
-      java.srcDirs += 'flavors/google-services-disabled'
+      java.srcDirs += 'flavors/gms-disabled'
+    }
+    if (googleFirebaseServicesEnabled) {
+      java.srcDirs += 'flavors/firebase-enabled'
+    } else {
+      java.srcDirs += 'flavors/firebase-disabled'
     }
 
     // assets folder is auto-generated by tools/android/update_assets.sh, so we keep all static resources in separate folders.
@@ -456,7 +489,7 @@ android {
       resValue 'string', 'app_id', android.defaultConfig.applicationId
       resValue 'string', 'app_name', project.ext.appName
       ndk.debugSymbolLevel = 'SYMBOL_TABLE'
-      if (googleServiceEnabled) {
+      if (googleFirebaseServicesEnabled) {
         firebaseCrashlytics {
           nativeSymbolUploadEnabled true
         }
@@ -471,7 +504,7 @@ android {
       resValue 'string', 'app_id', android.defaultConfig.applicationId + applicationIdSuffix
       resValue 'string', 'app_name', project.ext.appName + applicationIdSuffix
       ndk.debugSymbolLevel = 'SYMBOL_TABLE'
-      if (googleServiceEnabled) {
+      if (googleFirebaseServicesEnabled) {
         firebaseCrashlytics {
           nativeSymbolUploadEnabled true
         }