update MDC version

Author: mmalerba

package.json

@@ -37,7 +37,7 @@
   },
   "version": "8.1.2",
   "requiredAngularVersion": "^8.0.0 || ^9.0.0-0",
-  "requiredMDCVersion": "^3.0.0",
+  "requiredMDCVersion": "^4.0.0-alpha.0",
   "dependencies": {
     "@angular/animations": "^8.1.0",
     "@angular/common": "^8.1.0",
@@ -49,7 +49,7 @@
     "@types/youtube": "^0.0.38",
     "@webcomponents/custom-elements": "^1.1.0",
     "core-js": "^2.6.1",
-    "material-components-web": "^3.0.0",
+    "material-components-web": "^4.0.0-alpha.0",
     "rxjs": "^6.4.0",
     "systemjs": "0.19.43",
     "tsickle": "^0.35.0",
@@ -66,8 +66,8 @@
     "@angular/router": "^8.1.0",
     "@angular/upgrade": "^8.1.0",
     "@bazel/bazel": "^0.27.0",
-    "@bazel/hide-bazel-files": "0.32.2",
     "@bazel/buildifier": "^0.25.1",
+    "@bazel/hide-bazel-files": "0.32.2",
     "@bazel/ibazel": "^0.10.3",
     "@bazel/jasmine": "0.32.2",
     "@bazel/karma": "0.32.2",