Adjust Japanese translation

[sanak]

Problem
I noticed that some Japanese words needs to be translated same way.
(For example, note is translated ノート or メモ.)

Improvement
Japanese translation work will be online via Weblate (https://hosted.weblate.org/projects/smash/), but I want to keep changes on GitHub.

The following Geopaparazzi side Japanese translation can be used as a reference.

• ja: https://github.com/geopaparazzi/geopaparazzi/blob/master/geopaparazzi_core/src/main/res/values-ja/strings.xml
• en: https://github.com/geopaparazzi/geopaparazzi/blob/master/geopaparazzi_core/src/main/res/values/strings.xml

[sanak]

This was merged by the following upstream PR, so I close this.
https://github.com/geopaparazzi/smash/pull/187/files#diff-2cffe13b87b5700a0a3fd106458ac401adda8979f5971a88ffe65efd083497e1