Add Soong module definitions for ART run-tests with default build rules.

Introduce new Bash script `test/utils/regen-test-files` and use it
to generate a set of initial Soong module definitions for some ART
run-tests matching these conditions:
1. using default build rules (defined in `test/etc/default-build`), as
   per the `test/run-test` script;
2. consisting only of Java source files contained in their `src`
   directory;
3. containing no additional build complexity.

Also disable ErrorProne checks for ART run-tests on `errorprone`
builds.

Test: m $(find art/test \
              -regextype egrep \
              -regex 'art/test/[0-9]{3,}-.*/Android.bp' \
              -printf '%P\n' \
            | sed -r 's,(.*)/Android.bp,art-run-test-\1,' \
            | sort)
Test: m javac-check $(find art/test \
                          -regextype egrep \
                          -regex 'art/test/[0-9]{3,}-.*/Android.bp' \
                          -printf '%P\n' \
                        | sed -r 's,(.*)/Android.bp,art-run-test-\1,' \
                        | sort) RUN_ERROR_PRONE=true
Bug: 147814778
Change-Id: Ife6b045a88bd18b06a3fc202f3d226e27e0fc03d
diff --git a/test/526-long-regalloc/Android.bp b/test/526-long-regalloc/Android.bp
new file mode 100644
index 0000000..e68b8b2
--- /dev/null
+++ b/test/526-long-regalloc/Android.bp
@@ -0,0 +1,6 @@
+// Generated by `regen-test-files`. Do not edit manually.
+java_test {
+    name: "art-run-test-526-long-regalloc",
+    defaults: ["art-run-test-defaults"],
+    srcs: ["src/**/*.java"],
+}