[LSC] Add LOCAL_LICENSE_KINDS to external/libcxx

Added SPDX-license-identifier-Apache-2.0 SPDX-license-identifier-BSD
    SPDX-license-identifier-MIT SPDX-license-identifier-NCSA
to:
  Android.bp

Bug: 68860345
Bug: 151177513
Bug: 151953481

Test: m all

Exempt-From-Owner-Approval: janitorial work
Change-Id: I36daefefdf3ea2b62cdb56e2ac13a810091d5283
1 file changed