设置默认(未聚焦) TextInputLayout提示textSize

<com.google.android.material.textfield.TextInputLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    app:hintTextAppearance="@style/MyTextInputLayout">

    <com.google.android.material.textfield.TextInputEditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

</com.google.android.material.textfield.TextInputLayout>

<style name="MyTextInputLayout" parent="Widget.MaterialComponents.TextInputLayout.FilledBox">
    <item name="android:textSize">16sp</item>
</style>

TextInputLayout textInputLayout = findViewById(R.id.textInputLayout);
textInputLayout.setHintTextAppearance(R.style.MyTextInputLayout);