AudioFlinger: Extract inner AudioStreamIn and Source classes

Ensure member variables are const.

Test: atest audiorecord_tests audiotrack_tests audiorouting_tests trackplayerbase_tests audiosystem_tests
Test: atest AudioTrackTest AudioRecordTest
Test: YouTube Camera
Bug: 288339104
Bug: 290269791
Merged-In: Idb7586437ce43ae1c8455bcef645a943ad2e79de
Change-Id: Idb7586437ce43ae1c8455bcef645a943ad2e79de
diff --git a/services/audioflinger/Threads.cpp b/services/audioflinger/Threads.cpp
index 034c54a..0033314 100644
--- a/services/audioflinger/Threads.cpp
+++ b/services/audioflinger/Threads.cpp
@@ -9488,7 +9488,7 @@
     return ids;
 }
 
-AudioFlinger::AudioStreamIn* AudioFlinger::RecordThread::clearInput()
+AudioStreamIn* AudioFlinger::RecordThread::clearInput()
 {
     Mutex::Autolock _l(mLock);
     AudioStreamIn *input = mInput;
@@ -10902,7 +10902,7 @@
     return MmapThread::exitStandby_l();
 }
 
-AudioFlinger::AudioStreamIn* AudioFlinger::MmapCaptureThread::clearInput()
+AudioStreamIn* AudioFlinger::MmapCaptureThread::clearInput()
 {
     Mutex::Autolock _l(mLock);
     AudioStreamIn *input = mInput;