SF: Avoid allocation on hot path to IF

The number of layer stacks and listeners is small, and the predominant
operations are lookup and iteration respectively, so store them on the
stack contiguously to avoid hashing/allocation/indirection.

Preallocate the WindowInfo and DisplayInfo vectors, since reallocating
the former involves copying strings and fiddling with sp<> ref counts.

Bug: 185536303
Test: simpleperf
Test: WindowInfosListenerTest
Change-Id: I5d1d1fc3b2639a4ee5056697e1a3581c11174173