Clean up android desugar tool's flags a bit

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PiperOrigin-RevId: 150019741
MOS_MIGRATED_REVID=150019741

GitOrigin-RevId: ecc2ab1b3195cabd22730272c237a59b42f2e967
Change-Id: I232b84336865b02369d10575d816d8053bee3371
1 file changed
tree: 2c45d6edb438b1c1b50b05f53f29cefd64ed1227
  1. java/