Fix an issue that the syncTimestampToDisplayLocked incorrect

If the device turned on for a long time then the timestamp get biffer.
In this case, the conversion error between float<->nsecs_t also becomes
large enough to prevent the best timestamp selection. This causes frame
drops when timestamps get large enough.

Bug: 263096067
Test: Manual test after device is turned on for long time
Change-Id: I94c90b32a053f7c0c0816dadbef8a47e13c64b30