Use the new malloced info for NativeAllocationRegistry in NativeConverter

I did not measure, but the allocation is likely larger than 200 bytes
for a UConverter instance.

Bug: 138994281
Test: atest --test-mapping external/icu/android_icu4j/src/main/java/com/android/icu/charset:presubmit
Change-Id: Id1b90f555e7b5b65cafccaa45863c0b4ca6e444c
2 files changed