Add HIDE_BUBBLES reason into InputMethodDebug

CL[1] add a new HIDE_BUBBLES reason but didn't add
it into the InputMethodDebug. Add this reason for
showing correct debugging information.

[1]: I09f27b3c187a7bcfbef663cd3101a74ad8ab95ab

Bug: 244258828
Test: Verify this reason showing in SoftInputShowHideHistory
Change-Id: Ia571de9a00a05ab490152d40329a200fc40f0d6a