DisplayCutout: Fix attrs.xml javadoc

Fixes an issue with the javadoc for windowLayoutInDisplayCutoutMode.
Removes @tags from enum javadocs, because they get merged into a table,
which does not support inner @tags. Instead, use <code> tags which work
in that context.

Also replaces @see tags with {@link} tags in the attr javadoc, because
the enum value table gets appended, but it is invalid to have text after
an @see tag.

Change-Id: Ib97e9aa82e173d99a467132a0d403793d7297e61
Fixes: 76448223
Test: make doc-comment-check-docs, verify output at $ANDROID_BUILD_TOP/out/target/common/docs/doc-comment-check/reference/android/R.attr.html#windowLayoutInDisplayCutoutMode