Update SIPHeaderList to inherit SequencedCollection added in OpenJDK 21

java.util.List now extends SequencedCollection interface. java language
doesn't allow overloading a super-interface's method with
an incompatible return type.

In order to expose SequencedCollection API in the build time,
SIPHeaderList needs to be updated to return a compatible return type.

Issue: FP3-A13#318
Bug: 320460092
Bug: 346585466
Test: m droid
(cherry picked from https://android-review.googlesource.com/q/commit:ed499e64f2e8ac0cc3f7c8fbc87c1b28fb4fc185)
(cherry picked from https://android-review.googlesource.com/q/commit:c6e1674b95d19603d479b4b0555768f2524054a0)
Merged-In: Iea134996c36b670964c614a01e1f2cb26a76082e
Change-Id: Iea134996c36b670964c614a01e1f2cb26a76082e
(cherry picked from commit 5cc92755a2de0cf9c0f4fc50d9d677e5432c3f64)
1 file changed