This CL updates both the magnifier and the floating toolbar to use the
dialogCornerRadius attribute for the corner radius of their windows. In
both we use its value defined in the default device theme, rather than
the value defined in the application's custom theme.
Bug: 70848492
Test: atest CtsWidgetTestCases:android.widget.cts.MagnifierTest
Change-Id: Ifcf4cff1f38fd18b7dbb4c1802390e3beb92cd3c
(cherry picked from commit 3dcbc2112d)
Merged-In: Ifcf4cff1f38fd18b7dbb4c1802390e3beb92cd3c
fb4b6b8fd2