Harden 5G and carrier capability caching mechanisms

[Dhangofa]

Summary

This pull request introduces critical robustness improvements and security hardening to the device capability and carrier matching logic. It ensures that only verified, valid 5G capability results and carrier matches are cached, preventing false negatives, incorrect substring matches, and edge-case misconfigurations across different Android versions.

Changes & Improvements

1. 5G Capability Caching & Version Safeguards

• Version Floor Enforcement: Maintained Android 11 as the minimum OS version required for 5G capability detection, while preserving backward compatibility for Android 7–10 legacy behaviors.
• Profile ID Validation: Preserved forward-compatible profile ID checks for values 23 and higher.
• Negative Result Prevention:
  • Stopped empty default-network properties and unparseable property values from being incorrectly cached as "5G unsupported."
  • Restricted capability caching to instances where at least one valid numeric profile is successfully identified.

2. Carrier Alias Match Accuracy

• Strict Matching Rules:
  • Restricted short carrier aliases to exact matching to eliminate unrelated substring matches.
  • Implemented whole-phrase matching for longer carrier labels.
• Normalization & Registry:
  • Normalized common separators prior to phrase matching.
  • Preserved the maintained LTE-and-above carrier registry as valid real-world evidence.

3. Carrier Capability Validation & Caching

• Source Validation: Replaced the shell echo cache check with strict capability-source validation.
• Config Requirements:
  • Required at least one relevant, selected-slot CarrierConfig value before allowing cache persistence.
  • Ensured slot headers alone cannot validate default capability values.
• Optimistic Fallback: Preserved optimistic default behavior when CarrierConfig detection is unavailable.