Revert "Switch libplatformproto to sharedlib"

Bug:36847782

This reverts commit e5549d414c7231ee0037cf413dad17e28b8905ba.

Change-Id: I38f1c501b7e40be11ba5f0a7a50651e0c3e41fc5
diff --git a/Android.mk b/Android.mk
index eb649c9..8daab8f 100644
--- a/Android.mk
+++ b/Android.mk
@@ -1460,8 +1460,7 @@
 LOCAL_SRC_FILES := \
     $(call all-proto-files-under, core/proto) \
     $(call all-proto-files-under, libs/incident/proto)
-LOCAL_SHARED_LIBRARIES := libprotobuf-cpp-full
-include $(BUILD_SHARED_LIBRARY)
+include $(BUILD_STATIC_LIBRARY)
 
 # ====  c++ proto host library  ==============================
 include $(CLEAR_VARS)