Upgrade resize mode setting for home activities when restoring task

We need to convert the resize mode of home activities saved before
version 1 of the persisted task record if they are marked as
RESIZE_MODE_RESIZEABLE to RESIZE_MODE_RESIZEABLE_VIA_SDK_VERSION
since we didn't have that differentiation before version 1 and the
system didn't resize home activities before then.

Bug: 30982291
Bug: 32231084
Test: Verify that a device runnin N upgraded to O doesn't resize the
home activity when in split-screen multi-window mode.

Change-Id: I3c9dfcc8be2651b06f7ab77abe4edb9653742952