CEC: Fix OSD name message length

OSD name may be 1<=N<=14 characters long according to the CEC
specification.

CTS test: cect_11_2_11_1a_GiveOsdNameTest verifies the limit correctly.

Test: atest HdmiCecMessageBuilderTest
Bug: 165786024
Change-Id: I0b59c4753f974979101d9346081af597e3fc306f
2 files changed