Redesign the size compat restart button according to mocks.

The width of the hint is constant but the height changes with respect to the number of lines the text requires (see screenshots below). The X position of the hint is set programmatically so that the point's center will be aligned with the button's center.

Still need to add UI for different states of the button (pressed, focused, etc.) and maybe also the hint (since it's clickable). Mocks for this are still TBD.

Mocks: https://www.figma.com/file/fLAVOdDkg0lnFWiltSYbGA/Multitasking?node-id=2719%3A54196

Screenshots:
[default - 2 lines]    http://screen/4EtytFiKsY3Q5NE
[LTR language]         http://screen/9BSPipZYUd7UGPV
[short text - 1 line]  http://screen/AN5bds6rh5V55Bw
[large font - 3 lines] http://screen/6utG596y52LBDjX
[long text - 4 lines]  http://screen/7mBL2fXWy43UsTq

Bug: 198347324
Test: atest WMShellUnitTests:SizeCompatRestartButtonTest
Test: atest WMShellUnitTests:SizeCompatHintPopupTest
Test: atest atest WMShellUnitTests:SizeCompatUILayoutTest
Change-Id: Ida4c4171be94b60499cfe8acb6a2278f7e10a1f3