Frameworks/base: Add no-thread marking to zygote

Use ZygoteHooks code to mark zygote initialization to not be
allowed to create threads. This is helpful when new classes are
found to be used by apps but cannot be preloaded as they spawn
threads.

Bug: 27248115
Change-Id: I1dc3620d9e7d0054c672b993d89459fc4b353dfc