Modify dimens.xml and change full screen preview behavior

- Add w840dp which is for tablet's two-pane UX
- Change w600dp
- Hide navigation bar when enter FullPreviewActivity
- Don't cut workspace bottom at full preview if is FullPreviewActivity

Videos is using tablet portrait record temporarily because for now two pane settings width : apps width is 50 : 50 and the Figma doc is 30 : 70
Before: https://drive.google.com/file/d/11UoyF8NVUfVmiaKR5xeMLe8CydPij1no/view?usp=sharing&resourcekey=0-gPpSjqsmP5nvU5Z48j06Ew
After: https://drive.google.com/file/d/11A61lPOlNCkvZeCGL49PN2YZC41Zzm1p/view?usp=sharing&resourcekey=0-uZcMDuDARjFJ3c8ZT17QSA

Bug: 193374285
Test: Manual
Change-Id: Ia452a1df9d6ee042f48caffd1cb702111915716d
13 files changed