BufferHubQueue: ClearAvailable on consumer import

This fixes the issue that ConsumerQueue keeps receiving
|OnBufferAllocated| events when using UDS based libpdx. It also hardens
error handling during consumer imports.

Bug: 34690159
Test: Build, flash, buffer_hub_queue-test pases
Change-Id: I4f739a2869df851ed836f39122b3eba95697f3f6
diff --git a/libs/vr/libbufferhubqueue/Android.mk b/libs/vr/libbufferhubqueue/Android.mk
index 3ed7ff2..c70aaf4 100644
--- a/libs/vr/libbufferhubqueue/Android.mk
+++ b/libs/vr/libbufferhubqueue/Android.mk
@@ -40,6 +40,7 @@
 include $(CLEAR_VARS)
 LOCAL_SRC_FILES := $(sourceFiles)
 LOCAL_C_INCLUDES := $(includeFiles)
+LOCAL_CFLAGS := -DLOG_TAG=\"libbufferhubqueue\"
 LOCAL_EXPORT_C_INCLUDE_DIRS := $(includeFiles)
 LOCAL_STATIC_LIBRARIES := $(staticLibraries)
 LOCAL_SHARED_LIBRARIES := $(sharedLibraries)