The TBF tests are failing on some machines due to unexpected
log output: "DL packet loss of IMSI= / TLLI=0xffeeddcc: 0%"
These messages are printed if >= 1 second has passed between
loss reports. This timing is machine-dependent so the test
is unstable as a result. Only print these messages at log
level debug to (hopefully) make TBF tests pass consistently.
Update expected test output accordingly.
Change-Id: Ie43f0e3a8740f0fc132809a09a153886c51fadf9