Allow alert dialogs to inflate custom view layouts

Adds APIs to set a layout resource ID as an AlertDialog's custom view. To
make this useful for developers, also ensures that Dialog content is set
up when calls are made to Dialog.findViewById() before show().

BUG: 11136748
Change-Id: I29747a28d7e30f4e31fe474424109ff29e1eaa98
4 files changed