weaved: Disable RTTI

There is no longer a reliance on RTTI in libbrillo, so disable RTTI
in the rest of Brillo codebase.

Bug: 26292405
Change-Id: Ib4be977b8c5c73d1f3e4f4f445ced44015b96028
diff --git a/Android.mk b/Android.mk
index 7f8ac06..baf3bd5 100644
--- a/Android.mk
+++ b/Android.mk
@@ -70,7 +70,6 @@
 LOCAL_C_INCLUDES := $(buffetCommonCIncludes)
 LOCAL_SHARED_LIBRARIES := $(buffetSharedLibraries)
 LOCAL_STATIC_LIBRARIES :=
-LOCAL_RTTI_FLAG := -frtti
 LOCAL_CLANG := true
 LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH)
 
@@ -134,7 +133,6 @@
 LOCAL_STATIC_LIBRARIES := weaved-brillo-api
 LOCAL_WHOLE_STATIC_LIBRARIES := buffet-common
 LOCAL_CLANG := true
-LOCAL_RTTI_FLAG := -frtti
 
 LOCAL_SRC_FILES := \
 	buffet/main.cc
@@ -170,7 +168,6 @@
 	libweaved-internal \
 
 LOCAL_STATIC_LIBRARIES :=
-LOCAL_RTTI_FLAG := -frtti
 LOCAL_CLANG := true
 
 LOCAL_SRC_FILES := \
@@ -204,7 +201,6 @@
 	libweave-test \
 	weaved-brillo-api \
 
-LOCAL_RTTI_FLAG := -frtti
 LOCAL_CLANG := true
 
 LOCAL_SRC_FILES := \