Convert Launcher Android.mk to Android.bp to setup RoboTests

Bug: 181083996
Test: m Launcher3 && install Launcher3 and test basic things
Test: m RunLauncherRoboTests (90 tests run and 3 fails)

Change-Id: Icdc839d06413409cbd52d10a5ef9fe27b0a57baa
diff --git a/robolectric_tests/config/robolectric.properties b/robolectric_tests/config/robolectric.properties
index 4e811f3..1b170e1 100644
--- a/robolectric_tests/config/robolectric.properties
+++ b/robolectric_tests/config/robolectric.properties
@@ -1,4 +1,5 @@
 sdk=29
+
 shadows= \
     com.android.launcher3.shadows.LShadowAppPredictionManager \
     com.android.launcher3.shadows.LShadowAppWidgetManager \
@@ -11,4 +12,4 @@
     com.android.launcher3.shadows.ShadowOverrides \
     com.android.launcher3.shadows.ShadowSurfaceTransactionApplier \
 
-application=com.android.launcher3.util.LauncherTestApplication
\ No newline at end of file
+application=com.android.launcher3.util.LauncherTestApplication