Extract android_media_Utils.cpp as a lib

This is a part of job to cut dependency from libmediandk
to libandroid_runtime. As a LL-NDK, libmediandk desn't have
to depend on libandroid_runtime.

dependency: libmediandk -> libmedia_jni -> libandroid_runtime

Libmediandk calls three utility functions defined in
android_media_Utils.cpp. But these functions are independent
from libandroid_runtime.

By extracting those utility functions into its own shared library
(libmedia_jni_utils), the dependency from libmediandk to
libmedia_jni is cut down.

However, some classes and other functions in android_media_Utils.cpp
are moved into new file, android_media_Streams.cpp since they
depend on libandroid_runtime.

Bug: 124268753
Test: m -j
Change-Id: I1e1ea4bc1ff7022d8d9c42785c8c00e3ca153a50
Merged-In: I1e1ea4bc1ff7022d8d9c42785c8c00e3ca153a50