aaudio: lock transport methods

The start/pause/stop/flush/close and other binder methods
need to be thread safe. They do not need to run
in parallel. So a lock was added for each.

Where virtual methods are needed, the locked method calls
a corresponding _l submethod, eg. stop() calls stop_l().

The close logic was also simplified because the "pending"
technique is not needed now that we have the locks.
It was only needed because a close could have occured
while in the middle of another method.

This CL was merged with changes in RVC-DEV.

Bug: 153358911
Test: adb logcat *:F
Test: in another window:  test_binder_attack
Test: There should be no fatal error in the logcat.
Test: atest CtsNativeMediaAAudioTestCases
Change-Id: I5920cf78af4501856756c5c2fc8e77758232508a
diff --git a/services/oboeservice/AAudioServiceStreamMMAP.cpp b/services/oboeservice/AAudioServiceStreamMMAP.cpp
index 639a0a8..54d7d06 100644
--- a/services/oboeservice/AAudioServiceStreamMMAP.cpp
+++ b/services/oboeservice/AAudioServiceStreamMMAP.cpp
@@ -92,11 +92,11 @@
 }
 
 // Stop the flow of data such that start() can resume with loss of data.
-aaudio_result_t AAudioServiceStreamMMAP::pause() {
+aaudio_result_t AAudioServiceStreamMMAP::pause_l() {
     if (!isRunning()) {
         return AAUDIO_OK;
     }
-    aaudio_result_t result = AAudioServiceStreamBase::pause();
+    aaudio_result_t result = AAudioServiceStreamBase::pause_l();
     // TODO put before base::pause()?
     if (!mInService) {
         (void) stopClient(mClientHandle);
@@ -104,11 +104,11 @@
     return result;
 }
 
-aaudio_result_t AAudioServiceStreamMMAP::stop() {
+aaudio_result_t AAudioServiceStreamMMAP::stop_l() {
     if (!isRunning()) {
         return AAUDIO_OK;
     }
-    aaudio_result_t result = AAudioServiceStreamBase::stop();
+    aaudio_result_t result = AAudioServiceStreamBase::stop_l();
     // TODO put before base::stop()?
     if (!mInService) {
         (void) stopClient(mClientHandle);