Make the Settings split ratio configurable.

This new config will be overlayed in titan devices to update the split
ratio to 30/70

Bug: 215707431
Test: locally on device
Change-Id: I7bd193d7516939f5c4d434cd3333456c20e53a91

src/com/android/settings/activityembedding/ActivityEmbeddingRulesController.java

@@ -92,7 +92,7 @@ public class ActivityEmbeddingRulesController {
                 clearTop,
                 ActivityEmbeddingUtils.getMinCurrentScreenSplitWidthPx(context),
                 ActivityEmbeddingUtils.getMinSmallestScreenSplitWidthPx(context),
-                ActivityEmbeddingUtils.SPLIT_RATIO,
+                ActivityEmbeddingUtils.getSplitRatio(context),
                 LayoutDirection.LOCALE));
     }
 
@@ -198,7 +198,7 @@ public class ActivityEmbeddingRulesController {
                 SplitRule.FINISH_ADJACENT,
                 ActivityEmbeddingUtils.getMinCurrentScreenSplitWidthPx(mContext),
                 ActivityEmbeddingUtils.getMinSmallestScreenSplitWidthPx(mContext),
-                ActivityEmbeddingUtils.SPLIT_RATIO,
+                ActivityEmbeddingUtils.getSplitRatio(mContext),
                 LayoutDirection.LOCALE);
 
         mSplitController.registerRule(placeholderRule);