soong_ui: Construct the proper MODULES-IN-<dir name> for m* build commands.

Previously, any of the build commands (mma, mmma, etc...) would traverse
up the directory path until an Android build file has been found. That
directory path would eventually become the MODULES-IN-<dir name> build
target. The directory where the m* command was executed may contain a
build file in a sub directory. For that case, the build target is the
MODULES-IN-<dir name> where dir is the directory of the executed m*
command since the target has been constructed by the core makefile.

Bug: b/118730755
Test: Wrote and ran unit test cases. Ran "lunch", "m". Went to a
      directory in AOSP that had build files in sub directories and
      executed mma. Went to a directory that had only build files in
      parent directories and executed mma.

Change-Id: I9458cbc4bf0fc25bfb0848e96e92d261442d5cb0