Utilize fallback navbar height if the returned value is zero on Android10 and less.

app/src/main/java/org/thoughtcrime/securesms/components/InsetAwareConstraintLayout.kt

@@ -2,6 +2,7 @@ package org.thoughtcrime.securesms.components
 
 import android.content.Context
 import android.content.res.Configuration
+import android.os.Build
 import android.util.AttributeSet
 import androidx.constraintlayout.widget.ConstraintLayout
 import androidx.constraintlayout.widget.Guideline
@@ -133,7 +134,12 @@ open class InsetAwareConstraintLayout @JvmOverloads constructor(
     val isLtr = ViewUtil.isLtr(this)
 
     val statusBar = windowInsets.top
-    val navigationBar = windowInsets.bottom
+    val navigationBar = if (windowInsets.bottom == 0 && Build.VERSION.SDK_INT <= 29) {
+      ViewUtil.getNavigationBarHeight(resources)
+    } else {
+      windowInsets.bottom
+    }
+
     val parentStart = if (isLtr) windowInsets.left else windowInsets.right
     val parentEnd = if (isLtr) windowInsets.right else windowInsets.left