When normalizing -source and --release options, allow the last one to…

… win

previously --release always took precedence.

if/when Bazel defaults to using e.g. --release 9, legacy -source and -target
javacopts should be respected.

PiperOrigin-RevId: 192844963

src/java_tools/buildjar/java/com/google/devtools/build/buildjar/javac/JavacOptions.java

@@ -243,22 +243,28 @@ public boolean processOption(String option, Iterator<String> remaining) {
         case "-source":
           if (remaining.hasNext()) {
             source = remaining.next();
+            release = null;
           }
           return true;
         case "-target":
           if (remaining.hasNext()) {
             target = remaining.next();
+            release = null;
           }
           return true;
         case "--release":
           if (remaining.hasNext()) {
             release = remaining.next();
+            source = null;
+            target = null;
           }
           return true;
         default: // fall out
       }
       if (option.startsWith("--release=")) {
         release = option.substring("--release=".length());
+        source = null;
+        target = null;
         return true;
       }
       return false;