Fix failing unit tests for android.text.format.Formatter

An update was needed for I34ae16bb68a28e60b09a7c17ac3b1d5ab9ddbeea,
but was forgotten. The updated tests assume standardized SI rounding,
using powers of 1000 instead of the previous powers of 1024.

Bug: 27672362
Bug: 29871955
Change-Id: Ib42124e9ec24bcb1309c3c940c1d830a18c4802f