Placeholders and percentage formatter are best practice to help prevent
accidental translation errors, especially when mixing formatted strings
with literal percent signs.
Fix: 366201919
Flag: EXEMPT minor string format fix with no functionality change
Test: Use TalkBack to observe the state description of the seekbar;
observe description is unchanged (e.g. "60% left, 40% right")
Test: atest BalanceSeekBarTest
Change-Id: Ie9dcc9219d253795be31b39279ed9d01d8794f66
1b98e50809