Disable unused display area features

The amount of DisplayArea keeps growing.
Currently there are 51 areas by default.

The FEATURE_FULLSCREEN_MAGNIFICATION wasn't used for 4 years.
By disabling it, the amount is reduced from 51 to 38, which reduces
the overhead of traversal, configuration propagation and memory usage.

Bug: 154719717
Flag: EXEMPT skip unused initialization.
Test: atest WmTests:DisplayAreaPolicyBuilderTest# \
            testBuilder_defaultPolicy_hasMagnificationFeature
Change-Id: Ib24ebe737aec271b9cf2e01425d01bc071a3c91d