Fix IDE warnings and make some methods static

Julien LepillerSat Jun 06 19:33:58+0200 2020

7f932b9

nani/app/furiganatextview/src/androidTest/java
namelast commitdate
eu/Switch to AndroidXSat Apr 25 23:54:54+0200 2020
se/Add furiganaMon Apr 15 20:09:48+0200 2019