get-prebuilts: Use https for Term.apk fetch

* Use secure protocol when fetching prebuilt APKs to avoid a MITM attack
  that could send a malicious APK instead.

Change-Id: If9dfc8bdc6f5a8ac360f40fe3fb423455082d224
Merge remote-tracking branch 'cyan/cm-11.0' into cm-11.0