weblayer: increase allowed version skew to 4

This is necessary in the short term because we dropped 82.

BUG=1067701
TEST=none

Change-Id: Iee16ec4083e53cfa532ea5b2bbeb1111453d45cb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2135338Reviewed-by: John Abd-El-Malek <jam@chromium.org>
Commit-Queue: Scott Violet <sky@chromium.org>
Cr-Commit-Position: refs/heads/master@{#756358}

weblayer/browser/java/org/chromium/weblayer_private/WebLayerFactoryImpl.java

@@ -48,7 +48,7 @@ public final class WebLayerFactoryImpl extends IWebLayerFactory.Stub {
     @Override
     public boolean isClientSupported() {
         StrictModeWorkaround.apply();
-        return Math.abs(sClientMajorVersion - getImplementationMajorVersion()) <= 3;
+        return Math.abs(sClientMajorVersion - getImplementationMajorVersion()) <= 4;
     }
 
     /**