Camera: Update ZSL result container

The implemetation defined ZSL processor currently
relies on the deprecated 'libutils' Vector for storing
the result metadata. The 'do_destroy' method within the
vector implementation will try to reinterpret cast an
internal void storage pointer to 'CameraMetadata' which
can trigger CFI.
Avoid possible CFI asserts and switch the container to
the now recommended 'std::vector'.

Bug: 135535544
Test: Camera CTS
Change-Id: Ie66d170ab06148f6e5a4669cf1325e13bcc22dcc