Only make Recents activity invisible if not focused on TV devices.

Change was introduced in b/28246419 to fix Recents activity visibility
issues on TV, but was causing other issues on phones. So, only apply
rule on TV devices.

Bug: 28246419
Bug: 28943853
Change-Id: Icd19eae4ffa5e0a798bc9f63bc7a6c9a60422236
2 files changed