Fix unused dependencies flag propagation and detection

Author: JonathanPerry651

src/java_tools/buildjar/java/com/google/devtools/build/buildjar/javac/plugins/dependency/StrictJavaDepsPlugin.java

@@ -213,7 +213,9 @@ public void finish() {
               : canonicalizeTarget(dependencyModule.getTargetLabel());
 
       for (Path directJar : directJars) {
-        if (!explicitDeps.containsKey(directJar) && !implicitDeps.containsKey(directJar)) {
+        boolean isImplicitlyUsed = implicitDeps.containsKey(directJar)
+            && implicitDeps.get(directJar).getKind() != Dependency.Kind.INCOMPLETE;
+        if (!explicitDeps.containsKey(directJar) && !isImplicitlyUsed) {
           JarOwner owner = readJarOwnerFromManifest(NonPlatformJar.forClasspathJar(directJar));
           String label = owner.label().isPresent()
               ? canonicalizeTarget(owner.label().get())

src/main/java/com/google/devtools/build/lib/rules/java/JavaCompileActionBuilder.java

@@ -320,7 +320,7 @@ private CustomCommandLine buildParamFileContents(ImmutableList<String> javacOpts
     if (strictJavaDeps != StrictDepsMode.OFF) {
       result.add("--strict_java_deps", strictJavaDeps.toString());
     }
-    if (unusedDeps != StrictDepsMode.OFF) {
+    if (unusedDeps != StrictDepsMode.OFF && unusedDeps != StrictDepsMode.DEFAULT) {
       result.add("--experimental_unused_deps", unusedDeps.toString());
     }
     if (strictJavaDeps != StrictDepsMode.OFF || unusedDeps != StrictDepsMode.OFF) {