Add macros for declaring copied file licenses.

The PRODUCT_COPY_FILES is populated before definitions.mk mapping
source files to installed files that get copied unchanged.

Need to be able to declare license metadata for the copied files such
that similarly named files in different projects can have different
licenses.

Need a macro to convert target names to their corresponding license
metadata.

Bug: 68860345
Bug: 151177513
Bug: 151953481
Bug: 213388645
Bug: 210912771

Test: m nothing

Change-Id: Ic244b3525e72b6cd8c4c4305bf5ad430d6e24ccb