Modify getAndroidComponentXmlElement to handle activity-alias

Since aliases have both the `name` and `targetActivity` attributes, we
should check all identifying attributes in order to add
`<activity-alias>` elements as dataflow sources.

Author: egregius313

java/ql/lib/semmle/code/java/frameworks/android/Android.qll

@@ -26,7 +26,12 @@ class AndroidComponent extends Class {
 
   /** The XML element corresponding to this Android component. */
   AndroidComponentXmlElement getAndroidComponentXmlElement() {
-    result.getResolvedComponentName() = this.getQualifiedName()
+    // Find an element with an identifier matching the qualified name of the component.
+    // Aliases have two identifiers (name and target), so check both identifiers (if present).
+    exists(AndroidIdentifierXmlAttribute identifier |
+      identifier = result.getAnAttribute() and
+      result.getResolvedIdentifier(identifier) = this.getQualifiedName()
+    )
   }
 
   /** Holds if this Android component is configured as `exported` in an `AndroidManifest.xml` file. */