Change test number to be 7 digits instead of 5

5 digit numbers cause a premium number pop-up to appear if a sim is
inserted, which in turn causes subsequent CTS tests outside Telecom to
fail. Changed to use 5550000 as a starting point so that we're dialing a
dummy 7-digit number instead.

Test: manual cts run
Change-Id: I657fcfd568c2d815f0c271ef46e6b0ace6f588ce
1 file changed