Gallery2: Modified layout of main panel in photo editor interface.

1. Change shape of iconview to square.
2. Add label on the bottom of iconview.
3. Change main panel background to transparent.
4. Change pictures of bottom icons in main panel.
5. Remove preset item if it has for each model filter.
according to UX specification document.

Change-Id: I81034c2e26e5ff1844826f0810bb91bbbaceb1ad
CRs-Fixed: 988070 988051