cherry-pick from pi-dev docs: Replacing {#link with {@link

Several java files had the typo {#link (for cross-references to other
Javadocs) instead of the proper {@link format. This was confusing the
new doc publish tool (Mivi) since that's the format used for {# Django
comments #}.

Fixed a couple of links that had other errors (which prevented building
once the {# -> {@ was done) and other typos.

Replaced throughout the frameworks/base project; I'll need a separate CL
for the AndroidX fixes.

(Other files were not in the public Javadocs.)

Bug: 111925950
Test: make ds-docs
Change-Id: Ia06e1fffd814671289a1caebd5962aedc18a28d7
Original Change-Id: Ia06e1fffd814671289a1caebd5962aedc18a28d7
Exempt-From-Owner-Approval: Docs-only change