Fix setCurrency resetting fraction digits.

ICU DecimalFormat and java.text.DecimalFormat differ in their
definition of setCurrency in that the former is documented to leave the
minimum and maximum fraction digits untouched and the later updates it
to the default of the currency.

Since we implement java.text.DecimalFormat using the ICU DecimalFormat
we have to work around that difference.

Bug: 28893763

(cherry picked from commit 13659d2d064672bb89cc41ccc75eeb89096166b4)

Change-Id: I30d855c89fcec6f732a1b44cb4d9ad77afd729fc
2 files changed