@CanIgnoreReturnValue
    public Builder withMasterKeyUri(String val) {
      if (!val.startsWith(AndroidKeystoreKmsClient.PREFIX)) {
        throw new IllegalArgumentException(
            "key URI must start with " + AndroidKeystoreKmsClient.PREFIX);
      }
      if (!useKeystore) {
        throw new IllegalArgumentException(
            "cannot call withMasterKeyUri() after calling doNotUseKeystore()");
      }
      this.masterKeyUri = val;
      return this;
    }
Sets the master key URI that references the key in Android Keystore with which the keyset
gets encrypted.

<p>Only master keys stored in Android Keystore is supported. The URI must start with {@code
android-keystore://}.

<p>Android Keystore is only supported on Android M (API level 23) and later. On older
version, calling this method works but doesn't do anything.
java_src/src/main/java/com/google/crypto/tink/integration/android/AndroidKeysetManager.java