Convert Personal/Work tabs to rounded bubbles

Modernize the tabs in Sharesheet/Resolver to match All Apps.

Much of this is copied from the tabs implementation in All Apps.

Remove divider line below tabs (no longer needed).

More XML, less code.

Bug: 188589041

Test: Manual in light and dark themes
Test: atest ResolverActivityTest
Test: atest ChooserActivityTest
Change-Id: Ib23a1927d416d32714dd8c890dd412c73f9e573c