Replace CLOCK_MONOTONIC with SYSTEM_TIME_MONOTONIC

Using SYSTEM_TIME_MONOTONIC works for Android (where it translates to
CLOCK_MONOTONIC) and host targets, while CLOCK_MONOTONIC is not defined
on macOS.

Bug: 117921091
Test: existing tests should pass
Change-Id: I1fad472881830fb0701a320cf37319e083932ad4

libs/hwui/renderthread/DrawFrameTask.cpp

@@ -69,7 +69,7 @@ int DrawFrameTask::drawFrame() {
     LOG_ALWAYS_FATAL_IF(!mContext, "Cannot drawFrame with no CanvasContext!");
 
     mSyncResult = SyncResult::OK;
-    mSyncQueued = systemTime(CLOCK_MONOTONIC);
+    mSyncQueued = systemTime(SYSTEM_TIME_MONOTONIC);
     postAndWait();
 
     return mSyncResult;