Catch SecurityException when sending clip change broadcast.

This fixes an issue where the system server can crash if a
SecurityException occurs while a clip change broadcast is being sent.

If an app is not permitted to access clipboard, then the
clipboardAccessAllowed check throws a SecurityException. This is
ok when the exception can propogate back to a caller, such as when
setClipData has been called, but when this happens while a change
broadcast is being triggered it will instead crash the system.

Bug: 207333180
Test: atest ClipboardManagerTest
Test: atest ClipDescriptionTest
Change-Id: If18ce497a89335ed26c8996571448c2c083887e6