Added "caching" of the safetynet response

app/src/main/java/com/topjohnwu/magisk/redesign/safetynet/SafetynetViewModel.kt

@@ -34,7 +34,11 @@ class SafetynetViewModel(
             .subscribeK { resolveResponse(it.responseCode) }
             .add()
 
-        attest()
+        if (safetyNetResult >= 0) {
+            resolveResponse(safetyNetResult)
+        } else {
+            attest()
+        }
     }
 
     override fun notifyStateChanged() {
@@ -56,6 +60,7 @@ class SafetynetViewModel(
             val hasCtsPassed = response and SafetyNetHelper.CTS_PASS != 0
             val hasBasicIntegrityPassed = response and SafetyNetHelper.BASIC_PASS != 0
             val result = hasCtsPassed && hasBasicIntegrityPassed
+            safetyNetResult = response
             ctsState.value = hasCtsPassed
             basicIntegrityState.value = hasBasicIntegrityPassed
             currentState = if (result) PASS else FAILED
@@ -80,4 +85,8 @@ class SafetynetViewModel(
         }
     }
 
+    companion object {
+        private var safetyNetResult = -1
+    }
+
 }