Don't display bugreport progress when it recedes, for real...

The previous fix was taking account just the progress reported by dumpstate,
not progress/percentage. As such, it was not detecting the cases where the
percentage decreased but the progress didn't.

Bug: 37878670
Test: m -j32 adb_test && ./out/host/linux-x86/nativetest64/adb_test/adb_test --gtest_filter=BugreportTest.*

Change-Id: I5830028f3191a9b17f63aeed5c049b29fa7d1179