Implement LOCAL_TARGET_REQUIRED_MODULES

to allow a host module to specify LOCAL_TARGET_REQUIRED_MODULES
to indicate that the device module should be built.

Bug: b/64580523
Test: add "LOCAL_TARGET_REQUIRED_MODULES := \
      CtsDeviceOsTestApp CtsHostProcfsTestApp" to \
      cts/hostsidetests/os/Android.mk, run \
      `m -j CtsOsHostSideTestCases`, check \
      that CtsDeviceOsTestApp.apk was built

Change-Id: I1457a51f7cd922c059aa62955d8693b1a7539fd9