Move bazel_module property to a common file, and add it to filegroup.

This enables prototyping against aosp/1441774 to demonstrate mixed
builds with converted BUILD files.

Test: TH Presubmit
Test: USE_BAZEL_ANALYSIS=1 m libc && prebuilts/build-tools/linux-x86/bin/ninja -f out/combined-aosp_cf_x86_auto.ninja -t commands libc | grep bazel-out | wc -l # 2 build actions
Bug: 171263886

Change-Id: I7b5cd0449d043ba26a339a0ef98b562fc62e13c8