Create bootloader_message static library.

bootloader_messages merges bootloader_message_writer
and bootloader.cpp, so we can use the same library to
manage bootloader_message in normal boot and recovery mode.

Bug: 29582118

Change-Id: I9efdf776ef8f02b53911ff43a518e035e0c29618
(cherry picked from commit 2f272c0551f984e83bc5abaf240e0dddb38a3326)
diff --git a/uncrypt/Android.mk b/uncrypt/Android.mk
index 3613799..59084b0 100644
--- a/uncrypt/Android.mk
+++ b/uncrypt/Android.mk
@@ -15,27 +15,17 @@
 LOCAL_PATH := $(call my-dir)
 
 include $(CLEAR_VARS)
-LOCAL_CLANG := true
-LOCAL_SRC_FILES := bootloader_message_writer.cpp
-LOCAL_MODULE := libbootloader_message_writer
-LOCAL_STATIC_LIBRARIES := libbase libfs_mgr
-LOCAL_CFLAGS := -Werror
-LOCAL_C_INCLUDES := $(LOCAL_PATH)/..
-LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH)/include
-
-include $(BUILD_STATIC_LIBRARY)
-
-include $(CLEAR_VARS)
 
 LOCAL_CLANG := true
 LOCAL_SRC_FILES := uncrypt.cpp
 LOCAL_C_INCLUDES := $(LOCAL_PATH)/..
 LOCAL_MODULE := uncrypt
-LOCAL_STATIC_LIBRARIES := libbootloader_message_writer \
-                          libbase \
-                          liblog \
-                          libfs_mgr \
-                          libcutils
+LOCAL_STATIC_LIBRARIES := \
+    libbootloader_message \
+    libbase \
+    liblog \
+    libfs_mgr \
+    libcutils
 LOCAL_CFLAGS := -Werror
 LOCAL_INIT_RC := uncrypt.rc