Use byte count rather than string length for NMS component name check

Bug: 505067993
Test: atest NotificationManagerServiceTest
Flag: EXEMPT BUGFIX
Cherrypick-From: https://googleplex-android-review.googlesource.com/q/commit:e844e46351d53ae6f8fb8d35dbfeb0677dc0dbf1
Merged-In: Ie1bf232340770e1237f80177bb0b86eabeda3635
Change-Id: Ie1bf232340770e1237f80177bb0b86eabeda3635
2 files changed