AudioFlinger: Extract inner Client class

Test: atest audiorecord_tests audiotrack_tests audiorouting_tests trackplayerbase_tests audiosystem_tests
Test: atest AudioTrackTest AudioRecordTest
Test: YouTube and Camera
Bug: 288339104
Bug: 289135349
Merged-In: I5b2973c12b3d36663fadd2e5ed362602785e1447
Change-Id: I5b2973c12b3d36663fadd2e5ed362602785e1447
(cherry picked from commit 59867e43c84de5563c73043594e13941cd016246)
diff --git a/services/audioflinger/Threads.h b/services/audioflinger/Threads.h
index 8620c15..3d41f45 100644
--- a/services/audioflinger/Threads.h
+++ b/services/audioflinger/Threads.h
@@ -411,7 +411,7 @@
     virtual     sp<StreamHalInterface> stream() const = 0;
 
                 sp<IAfEffectHandle> createEffect_l(
-                                    const sp<AudioFlinger::Client>& client,
+                                    const sp<Client>& client,
                                     const sp<media::IEffectClient>& effectClient,
                                     int32_t priority,
                                     audio_session_t sessionId,
@@ -981,7 +981,7 @@
                 void        setVolumeForOutput_l(float left, float right) const override;
 
                 sp<Track>   createTrack_l(
-                                const sp<AudioFlinger::Client>& client,
+                                const sp<Client>& client,
                                 audio_stream_type_t streamType,
                                 const audio_attributes_t& attr,
                                 uint32_t *sampleRate,
@@ -1943,7 +1943,7 @@
     virtual sp<IMemory> pipeMemory() const { return mPipeMemory; }
 
             sp<AudioFlinger::RecordThread::RecordTrack>  createRecordTrack_l(
-                    const sp<AudioFlinger::Client>& client,
+                    const sp<Client>& client,
                     const audio_attributes_t& attr,
                     uint32_t *pSampleRate,
                     audio_format_t format,