Changeup: consilidate code, drop cache, change download

This changes up way too much:
- Moving most (all) of the code to main.ts instead of the numerous
  files
- Dropping the caching functionality, since it should be optional
- now we will only download the android sdk tools if they are not
  already present, including if ANDROID_SDK_ROOT is already set

package-lock.json

@@ -2170,14 +2170,6 @@
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       "dev": true
     },
-    "axios": {
-      "version": "0.19.2",
-      "resolved": "https://registry.npmjs.org/axios/-/axios-0.19.2.tgz",
-      "integrity": "sha512-fjgm5MvRHLhx+osE2xoekY70AhARk3a6hkN+3Io1jc00jtquGvxYlKlsFUhmUET0V5te6CcZI7lcv2Ym61mjHA==",
-      "requires": {
-        "follow-redirects": "1.5.10"
-      }
-    },
     "babel-jest": {
       "version": "24.9.0",
       "resolved": "https://registry.npmjs.org/babel-jest/-/babel-jest-24.9.0.tgz",
@@ -3720,29 +3712,6 @@
       "integrity": "sha512-r5wGx7YeOwNWNlCA0wQ86zKyDLMQr+/RB8xy74M4hTphfmjlijTSSXGuH8rnvKZnfT9i+75zmd8jcKdMR4O6jA==",
       "dev": true
     },
-    "follow-redirects": {
-      "version": "1.5.10",
-      "resolved": "https://registry.npmjs.org/follow-redirects/-/follow-redirects-1.5.10.tgz",
-      "integrity": "sha512-0V5l4Cizzvqt5D44aTXbFZz+FtyXV1vrDN6qrelxtfYQKW0KO0W2T/hkE8xvGa/540LkZlkaUjO4ailYTFtHVQ==",
-      "requires": {
-        "debug": "=3.1.0"
-      },
-      "dependencies": {
-        "debug": {
-          "version": "3.1.0",
-          "resolved": "https://registry.npmjs.org/debug/-/debug-3.1.0.tgz",
-          "integrity": "sha512-OX8XqP7/1a9cqkxYw2yXss15f26NKWBpDXQd0/uK/KPqdQhxbPa994hnzjcE2VqQpDslf55723cKPUOGSmMY3g==",
-          "requires": {
-            "ms": "2.0.0"
-          }
-        },
-        "ms": {
-          "version": "2.0.0",
-          "resolved": "https://registry.npmjs.org/ms/-/ms-2.0.0.tgz",
-          "integrity": "sha1-VgiurfwAvmwpAd9fmGF4jeDVl8g="
-        }
-      }
-    },
     "for-in": {
       "version": "1.0.2",
       "resolved": "https://registry.npmjs.org/for-in/-/for-in-1.0.2.tgz",
@@ -8544,14 +8513,6 @@
         "async-limiter": "~1.0.0"
       }
     },
-    "xml-js": {
-      "version": "1.6.11",
-      "resolved": "https://registry.npmjs.org/xml-js/-/xml-js-1.6.11.tgz",
-      "integrity": "sha512-7rVi2KMfwfWFl+GpPg6m80IVMWXLRjO+PxTq7V2CDhoGak0wzYzFgUY2m4XJ47OGdXd8eLE8EmwfAmdjw7lC1g==",
-      "requires": {
-        "sax": "^1.2.4"
-      }
-    },
     "xml-name-validator": {
       "version": "3.0.0",
       "resolved": "https://registry.npmjs.org/xml-name-validator/-/xml-name-validator-3.0.0.tgz",