Update documentation for the aapt_version attribute.

RELNOTES: Labels aapt as deprecated for aapt_version, and heavily endorses aapt2.
PiperOrigin-RevId: 254298897
diff --git a/src/main/java/com/google/devtools/build/lib/rules/android/AndroidRuleClasses.java b/src/main/java/com/google/devtools/build/lib/rules/android/AndroidRuleClasses.java
index baf5e60..8eaff64 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/android/AndroidRuleClasses.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/android/AndroidRuleClasses.java
@@ -857,13 +857,9 @@
           Select the version of aapt for this rule.<br/>
           Possible values:
           <ul>
-              <li><code>aapt_version = "aapt"</code>: Use aapt. This is the current default
-                behaviour, and should be used for production binaries.</li>
-              <li><code>aapt_version = "aapt2"</code>: Use aapt2. This is the new resource
-               packaging system that provides improved incremental resource processing, smaller apks
-               and more.</li>
-              <li><code>aapt_version = "auto"</code>: aapt is controlled by the
-                --android_aapt flag.</li>
+              <li><code>aapt_version = "aapt"</code>: Use aapt (deprecated).</li>
+              <li><code>aapt_version = "aapt2"</code>: Use aapt2. This provides improved
+                incremental resource processing, smaller apks and more.</li>
           </ul>
           <!-- #END_BLAZE_RULE.ATTRIBUTE --> */
           .add(