TF-2953 Set up Patrol tests

android/app/build.gradle

@@ -23,7 +23,7 @@ if (flutterVersionName == null) {
 
 def flutterMinSdkVersion = localProperties.getProperty('flutter.minSdkVersion')
 if (flutterMinSdkVersion == null) {
-    flutterMinSdkVersion = '19'
+    flutterMinSdkVersion = '21'
 }
 
 apply plugin: 'com.android.application'
@@ -54,6 +54,8 @@ android {
         manifestPlaceholders = [
                 'appAuthRedirectScheme': 'teammail.mobile'
         ]
+        testInstrumentationRunner "pl.leancode.patrol.PatrolJUnitRunner"
+        testInstrumentationRunnerArguments clearPackageData: "true"
     }
 
     compileOptions {
@@ -77,7 +79,15 @@ android {
             // Signing with the debug keys for now, so `flutter run --release` works.
             signingConfig signingConfigs.release
         }
+        debug {
+            minifyEnabled false
+        }
     }
+
+    testOptions {
+        execution "ANDROIDX_TEST_ORCHESTRATOR"
+    }
+
 }
 
 flutter {
@@ -90,4 +100,5 @@ dependencies {
     implementation 'androidx.work:work-runtime-ktx:2.7.0'
     implementation 'com.android.support:multidex:1.0.3'
     implementation 'androidx.window:window:1.0.0'
+    androidTestUtil "androidx.test:orchestrator:1.5.0"
 }