Add missing test dependencies for ApkVerityTest

By keeping block_device_writer_module in target_required, it avoids
build error of "missing variant: os:linux_glibc, arch:common", while
the test still run on forrest.

Test: forrest
Test: lunch flame-eng; atest ApkVerityTest
Test: lunch aosp_x86_64-eng; m ApkVerityTest
Bug: 112039386
Change-Id: I9cfa0928941b008e23c2a32bb47dae5369bd3201