Camera: skip unnecessary reconfig

Test: manual testing 3rd party camera app + hacked walleye
Bug: 111850901
Change-Id: Ia2977a290bb0bd706f500a3d39e0d996d50cbe1e

services/camera/libcameraservice/api1/Camera2Client.cpp

@@ -780,6 +780,7 @@ status_t Camera2Client::startPreviewL(Parameters &params, bool restart) {
     int lastJpegStreamId = mJpegProcessor->getStreamId();
     // If jpeg stream will slow down preview, make sure we remove it before starting preview
     if (params.slowJpegMode) {
+        if (lastJpegStreamId != NO_STREAM) {
             // Pause preview if we are streaming
             int32_t activeRequestId = mStreamingProcessor->getActiveRequestId();
             if (activeRequestId != 0) {
@@ -809,6 +810,7 @@ status_t Camera2Client::startPreviewL(Parameters &params, bool restart) {
                             __FUNCTION__, mCameraId, strerror(-res), res);
                 }
             }
+        }
     } else {
         res = updateProcessorStream(mJpegProcessor, params);
         if (res != OK) {