Allow "tel:" as phone prefix; more white space leniency.

Allow phone numbers to be prefixed with "tel:" specifically, for URI-style.
Also allow a second space in the number, between the 6th and 7th digits:
E.g. 555 555 5555.

Bug: 7178434
Change-Id: Idf6b61d0bb0da6d6329216d6e832bd26dc37ff2c