Add color to PhoneAccount objects (2/3)

Change-Id: I2c53dbf3275b4c46933cf23e228a10936145cb9f
diff --git a/Android.mk b/Android.mk
index b272445..395aacc 100644
--- a/Android.mk
+++ b/Android.mk
@@ -14,7 +14,7 @@
 LOCAL_CERTIFICATE := platform
 LOCAL_PRIVILEGED_MODULE := true
 
-LOCAL_PROGUARD_ENABLED := optimization
+LOCAL_PROGUARD_FLAGS := $(proguard.flags)
 
 # Workaround for "local variable type mismatch" error.
 LOCAL_DX_FLAGS += --no-locals