Adding parseSizesList, getSupportedPreviewSizes to CameraParameters.

Moved functionality to parse string of sizes from getSupportedPictureSizes
to parseSizesList.
Added getSupportedPreviewSizes which returns a list of supported preview sizes.

Change-Id: I435317427c1ee9623caef435f93e95d4476b7285
diff --git a/include/camera/CameraParameters.h b/include/camera/CameraParameters.h
index 5211c95..b2808f5 100644
--- a/include/camera/CameraParameters.h
+++ b/include/camera/CameraParameters.h
@@ -58,6 +58,7 @@
 
     void setPreviewSize(int width, int height);
     void getPreviewSize(int *width, int *height) const;
+    void getSupportedPreviewSizes(Vector<Size> &sizes) const;
     void setPreviewFrameRate(int fps);
     int getPreviewFrameRate() const;
     void setPreviewFormat(const char *format);