Remove unused Android.mk in NamespaceTest

After checking, the modules under these directories can not be built
because the upper-level directories lack Android.mk.
Even if these Android.mk are included, they cannot be tested correctly
with atest.

Bug: 319568429
Test: N/A
Change-Id: I797d2327e340fcd38cde03dd0f520ec756be5fc3
5 files changed