Bug 1481834 - Fix running robocop tests on debug builds. r=gbrown

Fix running robocop tests on debug builds.

This patch fixes multidex issues when running robocop on debug builds.

Differential Revision: https://phabricator.services.mozilla.com/D3422

--HG--
extra : moz-landing-system : lando

mobile/android/app/build.gradle

@@ -80,6 +80,7 @@ android {
         def isDebuggable = (!mozconfig.substs.MOZILLA_OFFICIAL) || (mozconfig.substs.NIGHTLY_BUILD && mozconfig.substs.MOZ_DEBUG)
         debug {
             debuggable isDebuggable 
+            multiDexKeepProguard file("${topsrcdir}/mobile/android/config/proguard/debug-robocop-keeps.cfg")
         }
         release {
             debuggable isDebuggable

mobile/android/config/proguard/debug-robocop-keeps.cfg

@@ -0,0 +1,2 @@
+-keep class org.mozilla.gecko.** { *; }
+-keep class com.robotium.solo.** { *; }

mobile/android/tests/browser/robocop/src/org/mozilla/gecko/FennecInstrumentationTestRunner.java

@@ -8,6 +8,7 @@ import android.app.KeyguardManager;
 import android.content.Context;
 import android.os.Bundle;
 import android.os.PowerManager;
+import android.support.multidex.MultiDex;
 import android.test.InstrumentationTestRunner;
 import android.util.Log;
 
@@ -22,6 +23,7 @@ public class FennecInstrumentationTestRunner extends InstrumentationTestRunner {
 
     @Override
     public void onCreate(Bundle arguments) {
+        MultiDex.install(getTargetContext());
         sArguments = arguments;
         if (sArguments == null) {
             Log.e("Robocop", "FennecInstrumentationTestRunner.onCreate got null bundle");