MediaTranscodingService: Separate jni file into a sperate library.

This is needed when we move MediaTranscodeManager into apex.
Also rework the MediaTranscodeManager test so it could be invoked with
instrument.

Bug: 145628554
Test: MediaTranscodeManagerTest.
Change-Id: If0572af30d3aa7b7189ea0fc89582b83dd0d5d35
diff --git a/media/jni/Android.bp b/media/jni/Android.bp
index d2294b3..7518496 100644
--- a/media/jni/Android.bp
+++ b/media/jni/Android.bp
@@ -21,7 +21,6 @@
         "android_media_MediaProfiles.cpp",
         "android_media_MediaRecorder.cpp",
         "android_media_MediaSync.cpp",
-        "android_media_MediaTranscodeManager.cpp",
         "android_media_ResampleInputStream.cpp",
         "android_media_Streams.cpp",
         "android_media_SyncParams.cpp",
@@ -166,3 +165,27 @@
         "-Wunreachable-code",
     ],
 }
+
+cc_library_shared {
+    name: "libmediatranscodemanager_jni",
+    srcs: [
+        "android_media_MediaTranscodeManager.cpp",
+    ],
+
+    shared_libs: [
+        "libandroid_runtime",
+        "libcutils",
+        "liblog",
+        "libmedia",
+    ],
+
+    export_include_dirs: ["."],
+
+    cflags: [
+        "-Wall",
+        "-Werror",
+        "-Wno-error=deprecated-declarations",
+        "-Wunused",
+        "-Wunreachable-code",
+    ],
+}