Add Strictmode scenarios

[fractalwrench]

Adds a scenario to test Strictmode:

• Disk writes on main thread
• Network requests on main thread

Also prevents the crash handler from crashing due to StrictMode policy violations in the disk write scenario.

[coveralls]

Pull Request Test Coverage Report for Build 1129

• 0 of 5 (0.0%) changed or added relevant lines in 1 file are covered.
• 9 unchanged lines in 4 files lost coverage.
• Overall coverage decreased (-0.1%) to 70.621%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
sdk/src/main/java/com/bugsnag/android/ExceptionHandler.java	0	5	0.0%

Files with Coverage Reduction	New Missed Lines	%
sdk/src/main/java/com/bugsnag/android/ExceptionHandler.java	1	48.72%
sdk/src/main/java/com/bugsnag/android/DefaultHttpClient.java	2	53.85%
sdk/src/main/java/com/bugsnag/android/DeviceData.java	3	77.44%
sdk/src/main/java/com/bugsnag/android/Client.java	3	52.58%

Totals
Change from base Build 1116:	-0.1%
Covered Lines:	1762
Relevant Lines:	2495

---

💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 1129

• 0 of 5 (0.0%) changed or added relevant lines in 1 file are covered.
• 9 unchanged lines in 4 files lost coverage.
• Overall coverage decreased (-0.1%) to 70.621%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
sdk/src/main/java/com/bugsnag/android/ExceptionHandler.java	0	5	0.0%

Files with Coverage Reduction	New Missed Lines	%
sdk/src/main/java/com/bugsnag/android/ExceptionHandler.java	1	48.72%
sdk/src/main/java/com/bugsnag/android/DefaultHttpClient.java	2	53.85%
sdk/src/main/java/com/bugsnag/android/DeviceData.java	3	77.44%
sdk/src/main/java/com/bugsnag/android/Client.java	3	52.58%

Totals
Change from base Build 1116:	-0.1%
Covered Lines:	1762
Relevant Lines:	2495

---

💛 - Coveralls