Make NetworkCapabilities publicly immutable.

Applying API council comments.

bug: 15142362

(cherry picked from commit Ie0bde68b72656a676d90c0343b9756fe9268d8d6)
Change-Id: Ie0bde68b72656a676d90c0343b9756fe9268d8d6
4 files changed
tree: 17548ed31c5a726f9e0a044d34166714956a713f
  1. core/
  2. services/
  3. tests/