rn,auth: don't auto-capitalize the password field

Fixes: https://github.com/jitsi/jitsi-meet/issues/5673

react/features/authentication/components/LoginDialog.native.js

                         underlineColorAndroid = { FIELD_UNDERLINE }
                         value = { this.state.username } />
                     <TextInput
+                        autoCapitalize = { 'none' }
                         onChangeText = { this._onPasswordChange }
                         placeholder = { t('dialog.userPassword') }
                         placeholderTextColor = { PLACEHOLDER_COLOR }