implement PIN/passphrase generation UI

Passphrases have been implemented using EFF's Long Wordlist of 6^5
words. In terms of entropy, an 8-word passphrase would have a search
space of (6^5)^8 ~= 2^103. This wordlist can be easily changed; just
make sure to update the various constants in the DicewareWordList class

Test: Manual
Test: atest -c SettingsUnitTests:com.android.settings.password.generate
(after building with m and running emulator)
Test: SetupWizard2

Author: inthewaves

AndroidManifest.xml

@@ -2977,6 +2977,13 @@
             android:enableOnBackInvokedCallback="false"
             android:exported="false" />
 
+        <activity android:name=".password.generate.GenerateLockPasswordActivity"
+            android:label="Generate"
+            android:excludeFromRecents="true"
+            android:theme="@style/GlifTheme.Light"
+            android:windowSoftInputMode="stateVisible|adjustResize"
+            android:exported="false" />
+
         <activity android:name=".password.SetNewPasswordActivity"
             android:theme="@android:style/Theme.NoDisplay"
             android:exported="true"