Convert (by copying) hidl_array from and to std::array.

* For example, hidl_array<T, 2, 3> can be converted to
  std::array<std::array<T, 3>, 2>.

* Uses operator= for copying.

* Also uses operator= when initializing an hidl_array
  (instead of memcpy'ing). This fixes potential memory
  issues for hidl_array<hidl_string>, for example.

Bug: 32883329

Test: libhidl_test
Change-Id: Idf7d080433aaed2c585fd4875f3411e5544a9e72
2 files changed