build: Android: add a cleanup function to remove temporary toolchain copies on build failure

git-svn-id: https://svn.resiprocate.org/rep/resiprocate/main@10322 ddefafc4-47db-0310-ae44-fa13212b10f2
rutil/dns/ares: add support for DNS server discovery on Android

git-svn-id: https://svn.resiprocate.org/rep/resiprocate/main@10323 ddefafc4-47db-0310-ae44-fa13212b10f2
rutil: add support for Android logging / logcat utility

git-svn-id: https://svn.resiprocate.org/rep/resiprocate/main@10324 ddefafc4-47db-0310-ae44-fa13212b10f2