Empty part of a bossbar is not always gray

In contrast to MCPE-161436, which was labeled as "working as intended," there's a need for Java to change, which seems unusual. Either Java should undergo modification, or MCPE-161436 ought to be reopened. Based on MCPE-161436, the empty sections of the boss bars are consistently gray on Bedrock since version 1.18.0.20, making it a valid parity issue.