Update DexLoadReporter to comply with the new reporting API

This is a partial cherry pick of commit
3bec94d7.

It is partial because it only adapts DexLoadReporter to use the new
reporter BaseDexClassLoader.Reporter API.

Bug: 38138251
Test: make
Merged-In: I2486522fb811f9fc58a44b92642f43a41e7d5bac

(cherry picked from commit 3bec94d7)

Change-Id: I4c41dbeb8a9297caac8b0eb936cf74832569f33e