Add consumerProguardFile

[andhie]

Prevent obfuscation of GMS ProviderInstaller

ion/ion/src/com/koushikdutta/ion/conscrypt/ConscryptMiddleware.java

Line 57 in 7ddf485

Class<?> providerInstaller = Class.forName("com.google.android.gms.security.ProviderInstaller");

Trying to alleviate Issue #782 , #647
But without GMS, Ion would still not work on pre-Lollipop devices with SSL enabled

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This change is

[kakai248]

I can confirm this fixes the issue for Android >=5.0. However, doing this will also make it stop working on <5.0 (not sure why). To fix it add this:

if(android.os.Build.VERSION.SDK_INT < android.os.Build.VERSION_CODES.LOLLIPOP) {
    Ion.getDefault(this).getConscryptMiddleware().enable(false);
}