Bump handlebars in /samples/angularelements-html-templatefile

Bumps [handlebars](https://github.com/wycats/handlebars.js) from 4.0.11 to 4.7.7.
- [Release notes](https://github.com/wycats/handlebars.js/releases)
- [Changelog](https://github.com/handlebars-lang/handlebars.js/blob/master/release-notes.md)
- [Commits](https://github.com/wycats/handlebars.js/compare/v4.0.11...v4.7.7)

---
updated-dependencies:
- dependency-name: handlebars
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <support@github.com>

samples/angularelements-html-templatefile/package-lock.json

@@ -8629,31 +8629,48 @@
       }
     },
     "handlebars": {
-      "version": "4.0.11",
-      "resolved": "https://registry.npmjs.org/handlebars/-/handlebars-4.0.11.tgz",
-      "integrity": "sha1-Ywo13+ApS8KB7a5v/F0yn8eYLcw=",
+      "version": "4.7.7",
+      "resolved": "https://registry.npmjs.org/handlebars/-/handlebars-4.7.7.tgz",
+      "integrity": "sha512-aAcXm5OAfE/8IXkcZvCepKU3VzW1/39Fb5ZuqMtgI/hT8X2YgoMvBY5dLhq/cpOvw7Lk1nK/UF71aLG/ZnVYRA==",
       "dev": true,
       "requires": {
-        "async": "^1.4.0",
-        "optimist": "^0.6.1",
-        "source-map": "^0.4.4",
-        "uglify-js": "^2.6"
+        "minimist": "^1.2.5",
+        "neo-async": "^2.6.0",
+        "source-map": "^0.6.1",
+        "uglify-js": "^3.1.4",
+        "wordwrap": "^1.0.0"
       },
       "dependencies": {
-        "async": {
-          "version": "1.5.2",
-          "resolved": "https://registry.npmjs.org/async/-/async-1.5.2.tgz",
-          "integrity": "sha1-7GphrlZIDAw8skHJVhjiCJL5Zyo=",
+        "minimist": {
+          "version": "1.2.5",
+          "resolved": "https://registry.npmjs.org/minimist/-/minimist-1.2.5.tgz",
+          "integrity": "sha512-FM9nNUYrRBAELZQT3xeZQ7fmMOBg6nWNmJKTcgsJeaLstP/UODVpGsr5OhXhhXg6f+qtJ8uiZ+PUxkDWcgIXLw==",
+          "dev": true
+        },
+        "neo-async": {
+          "version": "2.6.2",
+          "resolved": "https://registry.npmjs.org/neo-async/-/neo-async-2.6.2.tgz",
+          "integrity": "sha512-Yd3UES5mWCSqR+qNT93S3UoYUkqAZ9lLg8a7g9rimsWmYGK8cVToA4/sF3RrshdyV3sAGMXVUmpMYOw+dLpOuw==",
           "dev": true
         },
         "source-map": {
-          "version": "0.4.4",
-          "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.4.4.tgz",
-          "integrity": "sha1-66T12pwNyZneaAMti092FzZSA2s=",
+          "version": "0.6.1",
+          "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.6.1.tgz",
+          "integrity": "sha512-UjgapumWlbMhkBgzT7Ykc5YXUT46F0iKu8SGXq0bcwP5dz/h0Plj6enJqjz1Zbq2l5WaqYnrVbwWOWMyF3F47g==",
+          "dev": true
+        },
+        "uglify-js": {
+          "version": "3.15.1",
+          "resolved": "https://registry.npmjs.org/uglify-js/-/uglify-js-3.15.1.tgz",
+          "integrity": "sha512-FAGKF12fWdkpvNJZENacOH0e/83eG6JyVQyanIJaBXCN1J11TUQv1T1/z8S+Z0CG0ZPk1nPcreF/c7lrTd0TEQ==",
           "dev": true,
-          "requires": {
-            "amdefine": ">=0.0.4"
-          }
+          "optional": true
+        },
+        "wordwrap": {
+          "version": "1.0.0",
+          "resolved": "https://registry.npmjs.org/wordwrap/-/wordwrap-1.0.0.tgz",
+          "integrity": "sha1-J1hIEIkUVqQXHI0CJkQa3pDLyus=",
+          "dev": true
         }
       }
     },