Replace usages of littlemock with mockito

Littlemock appears to have been created as an alternative to
Mockito that would work on Android. Given that Mockito does
now work on Android and Littlemock has had no activity since
Aug 2012 it seems prudent to switch over to use Mockito instead.

https://code.google.com/archive/p/littlemock/

This is being done as part of the work to upgrade Mockito.

Bug: 32912773
Test: Build and install affected APKs, test using am instrument
Change-Id: Id0e57880ea66c5681b664bbfb534c96410544665
diff --git a/tests/TtsTests/Android.mk b/tests/TtsTests/Android.mk
index ed63e12..3c3cd77 100644
--- a/tests/TtsTests/Android.mk
+++ b/tests/TtsTests/Android.mk
@@ -20,7 +20,7 @@
 
 LOCAL_SRC_FILES := $(call all-subdir-java-files)
 
-LOCAL_STATIC_JAVA_LIBRARIES := littlemock junit legacy-android-test
+LOCAL_STATIC_JAVA_LIBRARIES := mockito-target legacy-android-test
 LOCAL_JAVA_LIBRARIES := android.test.runner
 
 LOCAL_PACKAGE_NAME := TtsTests