Load call forwarding flag from EF_CFF_CPHS when EF_CFIS is missing.

After loading EF_CFF_CPHS, use it to set mCallForwardingEnabled flag
if EF_CFIS record is missing or invalid.

Also fixes a few typos and updates an incorrect Javadoc comment.

Bug: 8554894
Change-Id: I3dfe3c915ad15b65781cd4e4d65cfa5c71a46ad6