workaround CollapsingToolbarLayout issue in support lib

Fix from https://issuetracker.google.com/issues/64065383#comment12

OpenKeychain/src/main/java/android/support/design/widget/FixedCollapsingToolbarLayout.java

@@ -0,0 +1,30 @@
+package android.support.design.widget;
+
+import android.content.Context;
+import android.support.v4.view.WindowInsetsCompat;
+import android.util.AttributeSet;
+
+public class FixedCollapsingToolbarLayout extends CollapsingToolbarLayout {
+
+    public FixedCollapsingToolbarLayout(Context context) {
+        this(context, null);
+    }
+
+    public FixedCollapsingToolbarLayout(Context context, AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    @Override
+    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
+        // During the super call to onMeasure(), we'll save a copy of mLastInsets,
+        // consume the insets of mLastInsets so the super call has no insets to work with,
+        // then re-assign mLastInsets to what it was before the super call.
+        WindowInsetsCompat oldInsets = mLastInsets;
+        if (mLastInsets != null) {
+            mLastInsets = mLastInsets.consumeSystemWindowInsets();
+        }
+        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
+        mLastInsets = oldInsets;
+    }
+
+}