Setup nighlty build + GitHub action

app/build.gradle

@@ -2,6 +2,7 @@ plugins {
     id 'com.android.application'
     id 'org.jetbrains.kotlin.android'
     id 'com.google.devtools.ksp' version '1.7.20-1.0.7'
+    id 'com.google.firebase.appdistribution' version '3.0.2'
 }
 
 android {
@@ -20,6 +21,21 @@ android {
         }
     }
 
+    signingConfigs {
+        debug {
+            keyAlias 'androiddebugkey'
+            keyPassword 'android'
+            storeFile file('./signature/debug.keystore')
+            storePassword 'android'
+        }
+        nightly {
+            keyAlias System.env.ELEMENT_ANDROID_NIGHTLY_KEYID ?: project.property("signing.element.nightly.keyId")
+            keyPassword System.env.ELEMENT_ANDROID_NIGHTLY_KEYPASSWORD ?: project.property("signing.element.nightly.keyPassword")
+            storeFile file('./signature/nightly.keystore')
+            storePassword System.env.ELEMENT_ANDROID_NIGHTLY_STOREPASSWORD ?: project.property("signing.element.nightly.storePassword")
+        }
+    }
+
     buildTypes {
         debug {
             resValue "string", "app_name", "ElementX dbg"
@@ -33,6 +49,24 @@ android {
             minifyEnabled false
             proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
         }
+
+        nightly {
+            initWith release
+            applicationIdSuffix ".nightly"
+            versionNameSuffix "-nightly"
+            resValue "string", "app_name", "ElementX nightly"
+            matchingFallbacks = ['release']
+            signingConfig signingConfigs.nightly
+            firebaseAppDistribution {
+                artifactType = "APK"
+                // releaseNotesFile = TODO
+                groups = "external-testers"
+                // This should not be required, but if I do not add the appId, I get this error:
+                // "App Distribution halted because it had a problem uploading the APK: [404] Requested entity was not found."
+                appId = "1:912726360885:android:e17435e0beb0303000427c"
+            }
+        }
+
     }
     compileOptions {
         sourceCompatibility JavaVersion.VERSION_1_8
@@ -60,15 +94,6 @@ android {
             }
         }
     }
-
-    signingConfigs {
-        debug {
-            keyAlias 'androiddebugkey'
-            keyPassword 'android'
-            storeFile file('./signature/debug.keystore')
-            storePassword 'android'
-        }
-    }
 }
 
 dependencies {

app/src/nightly/google-services.json

@@ -0,0 +1,40 @@
+{
+  "project_info": {
+    "project_number": "912726360885",
+    "firebase_url": "https://vector-alpha.firebaseio.com",
+    "project_id": "vector-alpha",
+    "storage_bucket": "vector-alpha.appspot.com"
+  },
+  "client": [
+    {
+      "client_info": {
+        "mobilesdk_app_id": "1:912726360885:android:e17435e0beb0303000427c",
+        "android_client_info": {
+          "package_name": "io.element.android.x.nightly"
+        }
+      },
+      "oauth_client": [
+        {
+          "client_id": "912726360885-e87n3jva9uoj4vbidvijq78ebg02asv2.apps.googleusercontent.com",
+          "client_type": 3
+        }
+      ],
+      "api_key": [
+        {
+          "current_key": "AIzaSyAFZX8IhIfgzdOZvxDP_ISO5WYoU7jmQ5c"
+        }
+      ],
+      "services": {
+        "appinvite_service": {
+          "other_platform_oauth_client": [
+            {
+              "client_id": "912726360885-e87n3jva9uoj4vbidvijq78ebg02asv2.apps.googleusercontent.com",
+              "client_type": 3
+            }
+          ]
+        }
+      }
+    }
+  ],
+  "configuration_version": "1"
+}