Modify ambiguous getId method in LinkSpan

- getId() in LinkSpan.java returns a String type which clashes with the same method in its superclass, this will make developer confused, and even make compile failed when OEM using gradle to compile SUW.

- For now we just annotate the old method with Deprecated and add a new method as a suggestion, hoping to avoid compile errors for applications that already depend on it. The old method should be removed sooner or later.

Bug: 256046112
Test: mannual and compile successfully.

Change-Id: I91060901a090bb53ce52654436ebf3445e53118d
diff --git a/main/src/com/google/android/setupdesign/span/LinkSpan.java b/main/src/com/google/android/setupdesign/span/LinkSpan.java
index 7d91012..7defbf9 100644
--- a/main/src/com/google/android/setupdesign/span/LinkSpan.java
+++ b/main/src/com/google/android/setupdesign/span/LinkSpan.java
@@ -73,10 +73,10 @@
 
   /* non-static section */
 
-  private final String id;
+  private final String link;
 
-  public LinkSpan(String id) {
-    this.id = id;
+  public LinkSpan(String link) {
+    this.link = link;
   }
 
   @Override
@@ -137,7 +137,16 @@
     drawState.setUnderlineText(false);
   }
 
+  public String getLink() {
+    return link;
+  }
+
+  /**
+   * @deprecated Method's return type clashes with its superclass. Use {@link #getLink()} instead.
+   * This will be removed in the future.
+   */
+  @Deprecated
   public String getId() {
-    return id;
+    return link;
   }
 }