AIDL source generation accounts for Bazel paths

The AIDL source generation rule sets include flags based on the relative
path of .aidl sources. For .aidl sources provided by Bazel targets, e.g.
in a filegroup, the same directory could be added to the include path
twice. Instead we need to ensure that if a Bazel source provides the
include path, that we don't add it again from a Soong source.

Bug: 229251008
Test: USE_BAZEL_ANALYSIS=1 m api-stubs-docs-non-updatable
Change-Id: I4997039003242b43e0e52ccf41729acb4ad11324