Fix some indenting issues with set__() function

Previously it looked like this:

public final class OuterClass {
  [...]
  public static final class InnerClass extends
      com.google.protobuf.nano.MessageNano {
    [...]
    public void setId(java.lang.String value) {
      if (value == null) {
    throw new java.lang.NullPointerException();
  }
  id_ = value;
      bitfield0_ |= 0x00000001;
    [...]
  }
  [...]
}

Now it looks like this:

public final class OuterClass {
  [...]
  public static final class InnerClass extends
      com.google.protobuf.nano.MessageNano {
    [...]
    public void setId(java.lang.String value) {
      if (value == null) throw new java.lang.NullPointerException();
      id_ = value;
      bitfield0_ |= 0x00000001;
    [...]
  }
  [...]
}

Change-Id: I2a9289b528f785c846210d558206d677aa13e9be