add native IPlayer interface implementation

Generalized the IPlayer implementation done for OpenSL ES
so that it can be used by other native audio players
Created two classes:
 - PlayerBase implementing the interfacin native AudioManager and
 IPlayer methods
 - TrackPlayerBase, a derived class specialized for AudioTrack.

Bug: 62027849
Test: verify regressions with OpenSL ES buffer queue player

Change-Id: If5ad21a3c1a243fba0b312001c5034102e6d6672
diff --git a/media/libaudioclient/Android.bp b/media/libaudioclient/Android.bp
index 166534f..d853946 100644
--- a/media/libaudioclient/Android.bp
+++ b/media/libaudioclient/Android.bp
@@ -22,6 +22,8 @@
         "IEffect.cpp",
         "IEffectClient.cpp",
         "ToneGenerator.cpp",
+        "PlayerBase.cpp",
+        "TrackPlayerBase.cpp",
     ],
     shared_libs: [
         "liblog",
@@ -30,6 +32,7 @@
         "libbinder",
         "libdl",
         "libaudioutils",
+        "libaudiomanager",
     ],
     export_shared_lib_headers: ["libbinder"],