fix(android): File.read().text wrongly returns null for JSON files on Android Q

[jquick-axway]

JIRA:
https://jira.appcelerator.org/browse/TIMOB-26954

Summary:

• Caused by Android Q returning mime-type "application/json" which Titanium's TiMimeTypeHelper Java class incorrectly interpreted as a binary type.
• Modified Ti.Blob object's "text" property to always return text, even if it's a binary type.
  • Now matches iOS' behavior.
• Modified Ti.Blob object's toString() method to only return blob's text if mime-type is a known text type, like how "text" property used to work.

Test:

1. Build and run the below code on Android Q (aka: Android 10).
2. Verify that an alert appears on screen reading: Success!

// Create the JSON data to test with.
var jsonOriginalData = {
	myBoolean: true,
	myNumber: 123.456,
	myString: "Hello World",
	myArray: [false, true, -1, 0, 1, 123.456, "", "My String"],
	myDictionary: {
		nestedBoolean: false,
		nestedNumber: -43.21,
		nestedString: "This is a test.",
		nestedArray: [true, 123, "Hello Again"],
	},
};
var jsonOriginalString = JSON.stringify(jsonOriginalData);

// Write above JSON data to file.
var jsonFile = Ti.Filesystem.getFile(Ti.Filesystem.applicationDataDirectory, "test.json");
jsonFile.write(jsonOriginalString);
Ti.API.info("@@@ JSON string written:\n" + jsonOriginalString);

// Read the JSON file that was just written above.
var jsonReadString = jsonFile.read().text;
Ti.API.info("@@@ JSON string read:\n" + jsonReadString);

// Check if JSON was written/read to/from file successfully.
if (jsonReadString === jsonOriginalString) {
	alert("Success!");
} else {
	alert("Failed!");
}

[build]

	Messages
📖	💾 Here's the generated SDK zipfile.
📖	✅ All tests are passing Nice one! All 3613 tests are passing. (There are 464 tests skipped)

Generated by 🚫 dangerJS against f33892b

[garymathews]

CR: PASS

[lokeshchdhry]

FR Passed.

JSON file is read successfully on Android Q.

Studio Ver: 5.1.3.201905231615
SDK Ver: 8.2.0 local build
OS Ver: 10.14.5
Xcode Ver: Xcode 10.2.1
Appc NPM: 4.2.13
Appc CLI: 7.0.12-70X.4
Daemon Ver: 1.1.3
Ti CLI Ver: 5.1.1
Alloy Ver: 1.13.10
Node Ver: 8.15.1
NPM Ver: 6.4.1
Java Ver: 10.0.2
Devices: Android Q emulator.