Don't override activity display adjustments with app config

When process configuration was applied on the client side it
accidentally applied an override to display adjustments in resources
for all ResourceImpl objects. This resulted in resources of
activities having incorrect display adjustments and reporting
incorrect display size.

This change fixes the issue by applying the activity's override
configuration on top of the app config before updating the
display adjustments.

Note: This is a slight revert/rework of Ib3ee007bc

Fixes: 148639826

Test: ActivityThreadTest#testHandleConfigurationChanged_DoesntOverrideActivityConfig
Change-Id: I08a5bc29443fbdefbca791240aeaff8f138b8756