Fix masking bug for TTS Aligner
# What does this PR do ?

Fixes a masking bug where boolean values were inverted from what was expected. Reverted change from PR #5653.

**Collection**: TTS

# Changelog 
- Added check for `== 0` (applied to the input mask) back to the Aligner forward call. Otherwise the mask is applied incorrectly, as the values are flipped from what is expected in the Aligner module.

**PR Type**:
- [ ] New Feature
- [x] Bugfix
- [ ] Documentation

# Additional Information
* See Issue #6584 
