This fix tries to address the issue raised in 26300. Previously
`docker images` will use `HumanSize()` to display the size which
has a fixed precision of 4 (thus 3 fractional digits). This
could be problematic in certain languages (e.g. , German, see
26300) as `.` may be interpreted as thousands-separator in number.
This fix use `CustomSize()` instead and limit the precision to 3
(thus 2 fractional digits).
This fix has been tested manually.
This fix fixes 26300.
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>
