Increase heap size for fast capture in stereo

Test: at bug
Bug: 66967812
Change-Id: I06423217e02f644452d6a03ae01316fd6d2d9145
diff --git a/services/audioflinger/Threads.cpp b/services/audioflinger/Threads.cpp
index 1585851..e202ca4 100644
--- a/services/audioflinger/Threads.cpp
+++ b/services/audioflinger/Threads.cpp
@@ -197,7 +197,7 @@
 // Initially this heap is used to allocate client buffers for "fast" AudioRecord.
 // Eventually it will be the single buffer that FastCapture writes into via HAL read(),
 // and that all "fast" AudioRecord clients read from.  In either case, the size can be small.
-static const size_t kRecordThreadReadOnlyHeapSize = 0x2000;
+static const size_t kRecordThreadReadOnlyHeapSize = 0x4000;
 
 // ----------------------------------------------------------------------------