separate metadatautils from rest of stagefright

metadatautils is used in mainline+framework. This gives us better
encapsulation for that code.

Bug: 245354160
Test: build and boot
Change-Id: I8e6aa7a1b11b52696263b271674936f3f752714c
diff --git a/media/module/mpeg2ts/Android.bp b/media/module/mpeg2ts/Android.bp
index 283df1e..bf762c6 100644
--- a/media/module/mpeg2ts/Android.bp
+++ b/media/module/mpeg2ts/Android.bp
@@ -51,6 +51,7 @@
         "libmedia_datasource_headers",
         "libaudioclient_headers",
         "media_ndk_headers",
+        "libstagefright_headers",
         "libstagefright_foundation_headers",
     ],