creating a new constant for Email field of third party intents

app/src/main/kotlin/com/simplemobiletools/contacts/pro/activities/EditContactActivity.kt

@@ -185,7 +185,7 @@ class EditContactActivity : ContactActivity() {
                 }
             }
 
-            val email = intent.getStringExtra("email")
+            val email = intent.getStringExtra(KEY_EMAIL)
             if (email != null) {
                 val newEmail = Email(email, DEFAULT_EMAIL_TYPE, "")
                 contact!!.emails.add(newEmail)

app/src/main/kotlin/com/simplemobiletools/contacts/pro/helpers/Constants.kt

@@ -30,6 +30,7 @@ const val REQUEST_CODE_SET_DEFAULT_DIALER = 1
 // extras used at third party intents
 const val KEY_PHONE = "phone"
 const val KEY_NAME = "name"
+const val KEY_EMAIL = "email"
 
 const val LOCATION_CONTACTS_TAB = 0
 const val LOCATION_FAVORITES_TAB = 1