CB-12154 file-transfer progressEvent.total = -1 on iOS

Makes chunkedMode=true uploads to contain Content-Length to make progress computable
diff --git a/src/ios/CDVFileTransfer.m b/src/ios/CDVFileTransfer.m
index 6024901..9b01049 100644
--- a/src/ios/CDVFileTransfer.m
+++ b/src/ios/CDVFileTransfer.m
@@ -229,6 +229,8 @@
         totalPayloadLength += [postBodyBeforeFile length] + [postBodyAfterFile length];
     }
 
+    [req setValue:[[NSNumber numberWithLongLong:totalPayloadLength] stringValue] forHTTPHeaderField:@"Content-Length"];
+
     if (chunkedMode) {
         CFReadStreamRef readStream = NULL;
         CFWriteStreamRef writeStream = NULL;
@@ -266,7 +268,6 @@
             CFRelease(writeStream);
         }];
     } else {
-        [req setValue:[[NSNumber numberWithLongLong:totalPayloadLength] stringValue] forHTTPHeaderField:@"Content-Length"];
         if (multipartFormUpload) {
             [postBodyBeforeFile appendData:fileData];
             [postBodyBeforeFile appendData:postBodyAfterFile];
@@ -814,7 +815,7 @@
     if (self.direction == CDV_TRANSFER_UPLOAD) {
         NSMutableDictionary* uploadProgress = [NSMutableDictionary dictionaryWithCapacity:3];
 
-        [uploadProgress setObject:[NSNumber numberWithBool:(!self.chunkedMode)] forKey:@"lengthComputable"];
+        [uploadProgress setObject:[NSNumber numberWithBool:true] forKey:@"lengthComputable"];
         [uploadProgress setObject:[NSNumber numberWithLongLong:totalBytesWritten] forKey:@"loaded"];
         [uploadProgress setObject:[NSNumber numberWithLongLong:totalBytesExpectedToWrite] forKey:@"total"];
         CDVPluginResult* result = [CDVPluginResult resultWithStatus:CDVCommandStatus_OK messageAsDictionary:uploadProgress];
diff --git a/tests/tests.js b/tests/tests.js
index 7149091..e303b45 100644
--- a/tests/tests.js
+++ b/tests/tests.js
@@ -1506,7 +1506,9 @@
                             obj = JSON.parse(uploadResult.response);
 
                             if (specContext.uploadOptions.chunkedMode) {
-                                expect(obj["content-length"]).not.toBeDefined("Expected Content-Length not to be defined");
+                                if (!isIos) {
+                                    expect(obj["content-length"]).not.toBeDefined("Expected Content-Length not to be defined");
+                                }
                                 expect(obj["transfer-encoding"].toLowerCase()).toEqual("chunked");
                             } else {
                                 expect(obj["content-length"]).toBeDefined("Expected Content-Length to be defined");