feat: add code sample and test for concatenating two input videos

[irataxy]

b:197546828

[snippet-bot]

Here is the summary of changes.

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• media/transcoder/src/create_job_with_concatenated_inputs.php:27, tag transcoder_create_job_with_concatenated_inputs

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[bshaffer]

The linter needs you to fix the following things:

-    $startTimeInput1Sec = (int)floor(abs($startTimeInput1));
-    $startTimeInput1Nanos = (int)(1000000000 * bcsub(abs($startTimeInput1), floor(abs($startTimeInput1)), 4));
-    $endTimeInput1Sec = (int)floor(abs($endTimeInput1));
-    $endTimeInput1Nanos = (int)(1000000000 * bcsub(abs($endTimeInput1), floor(abs($endTimeInput1)), 4));
+    $startTimeInput1Sec = (int) floor(abs($startTimeInput1));
+    $startTimeInput1Nanos = (int) (1000000000 * bcsub(abs($startTimeInput1), floor(abs($startTimeInput1)), 4));
+    $endTimeInput1Sec = (int) floor(abs($endTimeInput1));
+    $endTimeInput1Nanos = (int) (1000000000 * bcsub(abs($endTimeInput1), floor(abs($endTimeInput1)), 4));

-    $startTimeInput2Sec = (int)floor(abs($startTimeInput2));
-    $startTimeInput2Nanos = (int)(1000000000 * bcsub(abs($startTimeInput2), floor(abs($startTimeInput2)), 4));
-    $endTimeInput2Sec = (int)floor(abs($endTimeInput2));
-    $endTimeInput2Nanos = (int)(1000000000 * bcsub(abs($endTimeInput2), floor(abs($endTimeInput2)), 4));
+    $startTimeInput2Sec = (int) floor(abs($startTimeInput2));
+    $startTimeInput2Nanos = (int) (1000000000 * bcsub(abs($startTimeInput2), floor(abs($startTimeInput2)), 4));
+    $endTimeInput2Sec = (int) floor(abs($endTimeInput2));
+    $endTimeInput2Nanos = (int) (1000000000 * bcsub(abs($endTimeInput2), floor(abs($endTimeInput2)), 4));