Prevent proguard related crashloop on weather clock

A crashloop was happening due to "setGoneMargin" not being found.
Adding a proguard rule to keep ConstraintSet methods alleviates this.

Fixes: 322194308
Flag: N/A
Test: Change to weather clock, observe no crashloop
Change-Id: I322a89771b9535b27b68472c714ab33bb8a00814
diff --git a/packages/SystemUI/plugin/proguard_plugins.flags b/packages/SystemUI/plugin/proguard_plugins.flags
index abac27f..23ba8d0 100644
--- a/packages/SystemUI/plugin/proguard_plugins.flags
+++ b/packages/SystemUI/plugin/proguard_plugins.flags
@@ -7,3 +7,13 @@
 -keep class com.android.systemui.log.core.** {
     *;
 }
+
+# This type is used in the plugin API boundary, so ensure the used public methods are kept.
+-keepclassmembers class androidx.constraintlayout.widget.ConstraintSet {
+    public void connect(int, int, int, int, int);
+    public void constrainWidth(int, int);
+    public void constrainHeight(int, int);
+    public int getHeight(int);
+    public int getWidth(int);
+    public void setGoneMargin(int, int, int);
+}