Remove shouldInstallnewProgram()

Rate limiting based on program install time does not work very well in
networks with multiple routers / RAs.

Remove the functionality for now, since programs are only updated when
Ra#matches returns MATCH_PASS.

Test: atest ApfTest
Change-Id: I9359a79aaf0c36dfaab88e863019c254e94af72b
1 file changed