Import sources from xalan-tests xalan-j_2_7_3-rc10

Upstream source:
https://github.com/apache/xalan-test

The apache XML version in AOSP is 2.7.1. However, it's 16 years old.
The xalan-j_2_7_3-rc10 version of test sources is used because
there wasn't a clear manual how to build the tests in 2.7.1,
and many bugs are fixed.

However, org.apache.xalan.trace package in xalan-java
has to be imported due to dependency from the tests.

The commands:
mkdir -p test/trace-src/org/apache/xalan/
cp -R $REPO/xalan-java/src/org/apache/xalan/trace/ test/trace-src/org/apache/xalan/
cp -R $REPO/xalan-test/java/ test/
cp -R $REPO/xalan-test/tests/ test/
cp -R $REPO/xalan-test/tools/ test/
find test/java/ -type f -name "*.class" -delete # remove the unnecessary .class files

Bug: 283931833
Test: N/A
Change-Id: I740301fd740923112d869dbdcdaf3171618427bc
7476 files changed