droiddoc supports no_framework_libs.

follow: https://android-review.googlesource.com/c/platform/build/+/618046

Don't build agianst framwork libs when "no_framwork_libs" set to true.

Test: m -j
Bug: b/70351683
Change-Id: If6d37fac20c2b401aa30c31c14f1463300623a0e