emma code coverage filter for Browser

add emma code coverage filter to exclude com.android.common.* from
code coverage report because it's not actually in Browser source.

Change-Id: Ibd47eeeb5fec6a980ad27c24022dc939b06d6d1f
diff --git a/Android.mk b/Android.mk
index 6e20ab8..e015dda 100644
--- a/Android.mk
+++ b/Android.mk
@@ -12,6 +12,8 @@
 
 LOCAL_PACKAGE_NAME := Browser
 
+LOCAL_EMMA_COVERAGE_FILTER := *,-com.android.common.*
+
 include $(BUILD_PACKAGE)
 
 # additionally, build tests in sub-folders in a separate .apk