jpegrecoverymap: applyRecovery optimizations

Instead of computing pow(hdr_ratio, recovery) for each component
separately, compute it once per pixel.

Bug: 261877699
Test: push files from tests/data to /sdcard/Documents and then \
 atest libjpegdecoder_test libjpegencoder_test libjpegrecoverymap_test

Change-Id: I223c682f75c6c14c08f2fcdec69ab7a8d97d78a2