android: build.gradle comment cleanup

src/frontends/android/app/build.gradle

@@ -155,12 +155,10 @@ dependencies {
     implementation 'androidx.work:work-runtime-ktx:2.10.1'
     implementation 'com.google.android.material:material:1.13.0'
 
-    /* BOM 2026.06.01 = compose-ui 1.11.4. The Expressive API (MaterialExpressiveTheme,
+    /* BOM 2026.09.00 = compose 1.12. The Expressive API (MaterialExpressiveTheme,
        MotionScheme.expressive, LoadingIndicator, MaterialShapes) lives only in
-       material3 1.5.0-alpha/beta, so material3 is pinned explicitly.
-       1.5.0-beta01 is the newest line that still builds with AGP 8.13 / compileSdk 36:
-       alpha19+ (and 1.5.0-beta01, BOM 2026.09.00 = compose 1.12) require AGP 9.1 and
-       compileSdk 37. Unpin once those are adopted and 1.5.0 is stable. */
+       material3 1.5.0-alpha/beta, so material3 is pinned explicitly (needs AGP 9.1,
+       compileSdk 37, minSdk 24). Unpin once 1.5.0 is stable. */
     def composeBom = platform('androidx.compose:compose-bom:2026.09.00')
     implementation composeBom
     implementation 'androidx.compose.ui:ui'