ECB (Electronic Codebook) mode seems to be in use in the Captive Crypt sample for Android

[hawkinsji]

Describe the bug

The code uses ECB mode, which is generally deprecated.

Reproduction steps

Look at the code here and here for example.

• https://github.com/vmware/captive-web-view/blob/e831b0eb69c8cc947df39689e3999e4df8a28689/forAndroid/CaptiveCrypto/src/main/java/com/example/captivecrypto/StoredKey.kt#L353
• https://github.com/vmware/captive-web-view/blob/e831b0eb69c8cc947df39689e3999e4df8a28689/forAndroid/CaptiveCrypto/src/main/java/com/example/captivecrypto/StoredKey.kt#L330

Expected behavior

It's expected that ECB isn't used.

Additional context

No response