Add some comments for zoom methods.

Also change RuntimeException to IllegalArgumentException.
bug:2458926

Change-Id: I87af31f5f3f10244131a1117bd1725c2d292b587
1 file changed
tree: 8922e24a90a8b537ce679662287f01aa583f80bd
  1. camera/
  2. cmds/
  3. include/
  4. media/