fix: version file read happens only once (#160)

Co-authored-by: Ali Momen Sani <[email protected]>

Author: vagruchi

src/main/java/io/getstream/chat/java/services/framework/DefaultClient.java

@@ -95,7 +95,7 @@ private Retrofit buildRetrofitClient() {
                   .newBuilder()
                   .url(url)
                   .header("Content-Type", "application/json")
-                  .header("X-Stream-Client", "stream-java-client-" + getSdkVersion())
+                  .header("X-Stream-Client", "stream-java-client-" + sdkVersion)
                   .header("Stream-Auth-Type", "jwt")
                   .header("Authorization", jwtToken(apiSecret))
                   .build();
@@ -203,6 +203,8 @@ private static String getStreamChatBaseUrl(@NotNull Properties properties) {
     return url.toString();
   }
 
+  private static final @NotNull String sdkVersion = getSdkVersion();
+
   private static @NotNull String getSdkVersion() {
     var clsLoader = DefaultClient.class.getClassLoader();
     try (var inputStream = clsLoader.getResourceAsStream("version.properties")) {