Remove title number from specific chapter [duplicate]

Question

I want to remove the number of the title. In the picture you can find the problem as visually:

Is it possible? Thank you.

My MWE is below:

\RequirePackage{filecontents}
\begin{filecontents}{\jobname.bib}

@article{einstein,
    author = "Albert Einstein",
    title = "{Zur Elektrodynamik bewegter K{\"o}rper}. ({German})
    [{On} the electrodynamics of moving bodies]",
    journal = "Annalen der Physik",
    volume = "322",
    number = "10",
    pages = "891--921",
    year = "1905",
    DOI = "http://dx.doi.org/10.1002/andp.19053221004",
    keywords = "physics"
}

@book{dirac,
    title = {The Principles of Quantum Mechanics},
    author = {Paul Adrien Maurice Dirac},
    isbn = {9780198520115},
    series = {International series of monographs on physics},
    year = {1981},
    publisher = {Clarendon Press},
    keywords = {physics}
}

@online{knuthwebsite,
    author = "Donald Knuth",
    title = "Knuth: Computers and Typesetting",
    url  = "http://www-cs-faculty.stanford.edu/~uno/abcde.html",
    addendum = "(accessed: 01.09.2016)",
    keywords = "latex,knuth"
}

\end{filecontents}

\documentclass[12pt]{report}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[main=turkish,english,shorthands=:!]{babel}
\usepackage{titlesec}
\usepackage[normalem]{ulem}
\usepackage{etoolbox}
\usepackage[nottoc,numbib]{tocbibind}
\usepackage{titlesec}


% Customize headings
\usepackage{titlesec}
\newcommand*{\myonehalfvspace}{20.775861pt}% <-- Define a macro \myonehalfvspace


% Chapter heading \titlespacing*{command}{left}{before-sep}{after-sep}[right-sep]
\titleformat{\chapter}
  {\normalfont\normalsize\bfseries}{\thechapter.}{.5em}{}
\titlespacing{\chapter}{1cm}{0cm plus 4pt minus 2pt}{\myonehalfvspace plus 2pt minus 2pt}

\usepackage[round]{natbib}
\bibliographystyle{plainnat} % or some other suitable bib style

\usepackage[none]{hyphenat}

\usepackage[spaces,obeyspaces,hyphens]{xurl} % allow arbitrary line breaks in URL strings
\urlstyle{same}
\usepackage[colorlinks,allcolors=blue]{hyperref}


\begin{document}
\tableofcontents

\chapter{Chapter}
\setlength{\parindent}{1cm}

Chapter name and the first line of the paragraph is aligned here \cite{einstein}, \cite{dirac}, \cite{knuthwebsite}.

\chapter{Chapter}
Chapter 2 content.

\setlength\bibhang{50pt}
\bibliography{\jobname}

\chapter{Chapter}
Chapter 4 content.

\end{document}