Align outer edge of profile tabs and icons

Previously tabs were full-width, now they align with the outer edges of
icons.

In ResovlerActivity, this is constant. In ChooserActivity, the placement
of the icons is based upon the icon count and layout width, so it must
be computed at runtime.

Bug: 233330219
Test: Manually with various orientations across Chooser and Resolver.
Test: atest ResolverActivityTest, atest ChooserActivityTest
Change-Id: I2009211c277f6ea0b3f14a06a54e82f4c190c564