Use application context in DeviceFoldStateProvider

Get application context from the passed context in
DeviceFoldStateProvider as in case of using display context
the configuration won't be updated automatically.

We use display context in live wallpapers because Service
context doesn't return a display (Context#getDisplay) as Service
is not a UI context.

Application context will use default display's configuration which
should be acceptable as the rest of the code relies on the default
display too (e.g. screen callbacks are delivered only for the
default display). Application context's configuration is updated
normally on fold/unfold.

Bug: 377280470
Test: check that we don't play animation on rear camera selfie mode
Flag: EXEMPT bugfix
Change-Id: I989c2be83187816b247b3f41e5a3755be361592e