Phone: Display toast message for blank USSD request

As per spec 24.080, ussd response string should be
between 1 - 160.
When user requests SEND_USSD with blank/no
input, display toast message prompting user
to enter valid input.

Bug: 7471891
Change-Id: Ic7b7b89e8a683011048a19cabd1d36a27bbae953
Commits Ic7b7b89e8a683011048a19cabd1d36a27bbae953 and I471cad405aabe055f1757831ce7293ee182b3e6a translated to Russian

Fixed build failing trail

Change-Id: I8c1913f547344a0b955efc0ebaa43d7f90c0d4c9