Android-Framework hides the navigation bar by default and adds control display attributes

1. Environment

Qualcomm 865 Android 10

2. Source code modification

device/qcom/qssi/system.prop

@@ -217,3 +217,5 @@ persist.ruichi.gpu=2
 persist.ruichi.gpu_max=587
 persist.ruichi.gpu_min=305
 
+# Show navigation bar, 0 for display, 1 for hidden
+persist.navbar.status=1

frameworks/base/services/core/java/com/android/server/wm/DisplayPolicy.java

@@ -737,7 +737,7 @@ public class DisplayPolicy {
 
             // Allow a system property to override this. Used by the emulator.
             // See also hasNavigationBar().
-            String navBarOverride = SystemProperties.get("qemu.hw.mainkeys");
+            String navBarOverride = SystemProperties.get("persist.navbar.status");  //qemu.hw.mainkeys
             if ("1".equals(navBarOverride)) {
                 mHasNavigationBar = false;
             } else if ("0".equals(navBarOverride)) {