Limiting the magnified region

1. Get the real display size including the status and navigation bar.
2. Calculate the real position of magnification frame
(i.e. mirror window) based on the magnified region should be limited
by the region of the display.

Bug: 143451908
Test: manual test
Change-Id: I907b005f960bc2e254b73691d7ac8d80cdf92a16