aaudio: keep track of streams using strong pointers

Maintain strong pointer to service stream during service calls.
Use simple AAudioStreamTracker instead of complex HandleTracker.

Bug: 65280854
Test: affects all MMAP streams, run all CTS tests, etcetera
Change-Id: I3d2ed8b588ea39c216dacd4dea503b11c33f36f3
diff --git a/services/oboeservice/AAudioServiceEndpoint.cpp b/services/oboeservice/AAudioServiceEndpoint.cpp
index cba5bc8..3095bc9 100644
--- a/services/oboeservice/AAudioServiceEndpoint.cpp
+++ b/services/oboeservice/AAudioServiceEndpoint.cpp
@@ -60,7 +60,7 @@
     result << "    Reference Count:      " << mOpenCount << "\n";
     result << "    Requested Device Id:  " << mRequestedDeviceId << "\n";
     result << "    Device Id:            " << getDeviceId() << "\n";
-    result << "    Registered Streams:  " << "\n";
+    result << "    Registered Streams:" << "\n";
     result << AAudioServiceStreamShared::dumpHeader() << "\n";
     for (const auto stream : mRegisteredStreams) {
         result << stream->dump() << "\n";