Fix return type documentation for camera ndk methods

for
- ACameraCaptureSession_stopRepeating()
- ACameraCaptureSession_abortCaptures()

Bug: 355694957

Flag: DOCS_ONLY

Test: builds

Change-Id: Iea15a95e006bdb2ff109579bf42de595bfaac9d1
Signed-off-by: Jayant Chowdhary <jchowdhary@google.com>