Sets the specified 2-byte UTF-16 character at the current
{@code writerIndex} and increases the {@code writerIndex} by {@code 2}
in this buffer. The 16 high-order bits of the specified value are ignored.
If {@code this.writableBytes} is less than {@code 2}, {@link #ensureWritable(int)}
will be called in an attempt to expand capacity to accommodate.
Sets the specified 2-byte UTF-16 character at the current {@code writerIndex} and increases the {@code writerIndex} by {@code 2} in this buffer. The 16 high-order bits of the specified value are ignored. If {@code this.writableBytes} is less than {@code 2}, {@link #ensureWritable(int)} will be called in an attempt to expand capacity to accommodate.