Visualizer: Fix deadlock on close

Visualizer gets stuck in mCaptureThread::requestExitAndWait due to a
deadlock between mCaptureThread::mRunning and mCaptureLock.

Temporarily release mCaptureLock upon mCaptureThread::requestExitAndWait.

Test: Clarity -> Response, rapidly toggle visualizer enable, disable
Bug: 135326776
authored-by: Weiyin Jiang <wjiang@codeaurora.org>
Change-Id: If32431c4d7b271b7ea61168cb1a5a42f3a1cd66e

media/jni/audioeffect/Visualizer.cpp

@@ -78,10 +78,13 @@ status_t Visualizer::setEnabled(bool enabled)
     if (t != 0) {
         if (enabled) {
             if (t->exitPending()) {
+                mCaptureLock.unlock();
                 if (t->requestExitAndWait() == WOULD_BLOCK) {
+                    mCaptureLock.lock();
                     ALOGE("Visualizer::enable() called from thread");
                     return INVALID_OPERATION;
                 }
+                mCaptureLock.lock();
             }
         }
         t->mLock.lock();