Change format and units of logs in LegacyResampler

Fixed the logging format of std::chrono::duration types because C++20
adds their stream operator, and units were duplicated. Likewise, changed
from nanoseconds to milliseconds given that it is easier to reason the
logging messages in millis.

Bug: 297226446
Flag: EXEMPT refactor
Test: TEST=libinput_tests; m $TEST && $ANDROID_HOST_OUT/nativetest64/$TEST/$TEST
Change-Id: Idd06e4fbad4dd02a3bf28957004b4bdb00988325