Support Xcode-managed codesigning and update build instructions

submodules/BuildConfig/BUILD

@@ -7,6 +7,8 @@ load(
     "telegram_is_appstore_build",
     "telegram_appstore_id",
     "telegram_app_specific_url_scheme",
+    "telegram_enable_icloud",
+    "telegram_enable_siri",
 )
 
 objc_library(
@@ -25,6 +27,8 @@ objc_library(
         "-DAPP_CONFIG_IS_APPSTORE_BUILD={}".format(telegram_is_appstore_build),
         "-DAPP_CONFIG_APPSTORE_ID={}".format(telegram_appstore_id),
         "-DAPP_SPECIFIC_URL_SCHEME=\\\"{}\\\"".format(telegram_app_specific_url_scheme),
+        "-DAPP_CONFIG_IS_ICLOUD_ENABLED={}".format("true" if telegram_enable_icloud else "false"),
+        "-DAPP_CONFIG_IS_SIRI_ENABLED={}".format("true" if telegram_enable_siri else "false"),
     ],
     hdrs = glob([
         "PublicHeaders/**/*.h",

submodules/BuildConfig/PublicHeaders/BuildConfig/BuildConfig.h

@@ -18,6 +18,8 @@
 @property (nonatomic, readonly) bool isAppStoreBuild;
 @property (nonatomic, readonly) int64_t appStoreId;
 @property (nonatomic, strong, readonly) NSString * _Nonnull appSpecificUrlScheme;
+@property (nonatomic, readonly) bool isICloudEnabled;
+@property (nonatomic, readonly) bool isSiriEnabled;
 
 + (DeviceSpecificEncryptionParameters * _Nonnull)deviceSpecificEncryptionParameters:(NSString * _Nonnull)rootPath baseAppBundleId:(NSString * _Nonnull)baseAppBundleId;
 - (NSData * _Nullable)bundleDataWithAppToken:(NSData * _Nullable)appToken signatureDict:(NSDictionary * _Nullable)signatureDict;

submodules/BuildConfig/Sources/BuildConfig.m

@@ -185,6 +185,14 @@ API_AVAILABLE(ios(10))
     return @(APP_SPECIFIC_URL_SCHEME);
 }
 
+- (bool)isICloudEnabled {
+    return APP_CONFIG_IS_ICLOUD_ENABLED;
+}
+
+- (bool)isSiriEnabled {
+    return APP_CONFIG_IS_SIRI_ENABLED;
+}
+
 + (NSString * _Nullable)bundleSeedId {
     NSDictionary *query = [NSDictionary dictionaryWithObjectsAndKeys:
        (__bridge NSString *)kSecClassGenericPassword, (__bridge NSString *)kSecClass,