ANDROID: added memory initialization tests to cuttlefish config

Build the cuttlefish kernel with CONFIG_TEST_STACKINIT=y and
CONFIG_TEST_MEMINIT=y to provide the tests for stack and heap
initialization.

Bug: 144999193
Test: run cuttlefish and observe the following lines in dmesg:
      test_stackinit: all tests passed!
      test_meminit: all 130 tests passed!

Change-Id: I044347880de82211d9a58449ee3e558c570bda31
Signed-off-by: Alexander Potapenko <glider@google.com>