Telephony: Decode SPN from RuimRecords properly

To address issues with incorrect encoding scheme programmed
in some commercial CSIM cards, the decoded SPN is checked to
have characters in printable ASCII range. If not, they are
decoded with ENCODING_GSM_7BIT_ALPHABET scheme.

Change-Id: I5ae06e0d3df5a3b5b080cc6e69a73daaff92cb10
Merge "Telephony: Decode SPN from RuimRecords properly" into cm-10.2