Add a method to associate MediaDrm session with MediaCrypto

Previously, to associate a MediaDrm session with MediaCrypto,
the MediaDrm sessionId was passed as initData to the MediaCrypto
constructor.  This is not ideal for two reasons: it's pretty
obscure and you can't change the association without tearing
down the MediaCodec/MediaCrypto and starting all over.  Use
cases like key rotation require being able to update the
MediaDrm session post-construction.  This CL addresses both of
these issues.

bug: 19570317
Change-Id: Ieb32d04d61742fc1dee2105dd904690d44c46c7b
diff --git a/media/libmediaplayerservice/Crypto.h b/media/libmediaplayerservice/Crypto.h
index d5f3c50..99ea95d 100644
--- a/media/libmediaplayerservice/Crypto.h
+++ b/media/libmediaplayerservice/Crypto.h
@@ -47,6 +47,8 @@
 
     virtual void notifyResolution(uint32_t width, uint32_t height);
 
+    virtual status_t setMediaDrmSession(const Vector<uint8_t> &sessionId);
+
     virtual ssize_t decrypt(
             bool secure,
             const uint8_t key[16],