[MediaStream WPT] Make getSupportedConstraints() test HTTPS only

This test tests navigator.mediaDevices.getSupportedConstraints(),
but navigator.mediaDevices has recently become SecureContext in the
spec, so the test should be run with HTTPS.

Bug: 957546
Change-Id: I70608398481b1891eee77ecd8361aa9f03ac87ea
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1587031Reviewed-by: Florent Castelli <orphis@chromium.org>
Commit-Queue: Guido Urdaneta <guidou@chromium.org>
Cr-Commit-Position: refs/heads/master@{#654831}

third_party/blink/web_tests/external/wpt/mediacapture-streams/MediaDevices-getSupportedConstraints-expected.txt

-This is a testharness.js-based test.
-FAIL navigator.mediaDevices.getSupportedConstraints exists assert_inherits: provided value is not an object
-FAIL width is supported Cannot read property 'getSupportedConstraints' of undefined
-FAIL height is supported Cannot read property 'getSupportedConstraints' of undefined
-FAIL aspectRatio is supported Cannot read property 'getSupportedConstraints' of undefined
-FAIL frameRate is supported Cannot read property 'getSupportedConstraints' of undefined
-FAIL facingMode is supported Cannot read property 'getSupportedConstraints' of undefined
-FAIL resizeMode is supported Cannot read property 'getSupportedConstraints' of undefined
-FAIL volume is supported Cannot read property 'getSupportedConstraints' of undefined
-FAIL sampleRate is supported Cannot read property 'getSupportedConstraints' of undefined
-FAIL sampleSize is supported Cannot read property 'getSupportedConstraints' of undefined
-FAIL echoCancellation is supported Cannot read property 'getSupportedConstraints' of undefined
-FAIL autoGainControl is supported Cannot read property 'getSupportedConstraints' of undefined
-FAIL noiseSuppression is supported Cannot read property 'getSupportedConstraints' of undefined
-FAIL latency is supported Cannot read property 'getSupportedConstraints' of undefined
-FAIL channelCount is supported Cannot read property 'getSupportedConstraints' of undefined
-FAIL deviceId is supported Cannot read property 'getSupportedConstraints' of undefined
-FAIL groupId is supported Cannot read property 'getSupportedConstraints' of undefined
-Harness: the test ran to completion.
-