Add OpusDecoder test and fix 3-byte int sign extension bug in DEX parser

[Copilot]

Adds test for com/google/android/exoplayer2/ext/opus/OpusDecoder class parsing. Test initially failed due to incorrect 3-byte integer parsing in the DEX encoded value parser.

Bug Fix

The encodedValueIntParser incorrectly handled sign extension for 3-byte integers in little-endian format:

// Before (incorrect): checked LSB and prepended extension byte
const firstByte = uint8Array[0];
const firstBit = (firstByte & 0b1000_0000) >> 7;
const buffer = Buffer.from([ extensionByte, ...uint8Array ]);

// After (correct): check MSB and append extension byte  
const lastByte = uint8Array[uint8Array.length - 1];
const signBit = (lastByte & 0b1000_0000) >> 7;
const buffer = Buffer.from([ ...uint8Array, extensionByte ]);

This bug caused 0xbb80 (48000) to parse as 0xbb80ff (12288255).

Changes

• Add OpusDecoder to test suite for CID bafybeicb3qajmwy6li7hche2nkucvytaxcyxhwhphmi73tgydjzmyoqoda
• Fix 3-byte integer sign extension to use most significant byte in little-endian order

Original prompt

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This section details on the original issue you should resolve

<issue_title>Add bafybeicb3qajmwy6li7hche2nkucvytaxcyxhwhphmi73tgydjzmyoqoda + com/google/android/exoplayer2/ext/opus/OpusDecoder parseDexAgainstSmaliMacro test like others and make it pass</issue_title>
<issue_description></issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Add bafybeicb3qajmwy6li7hche2nkucvytaxcyxhwhphmi73tgydjzmyoqoda + com/google/android/exoplayer2/ext/opus/OpusDecoder parseDexAgainstSmaliMacro test like others and make it pass #177

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[coveralls]

Pull Request Test Coverage Report for Build 19371681162

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Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.002%) to 94.171%

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Totals
Change from base Build 19371639573:	0.002%
Covered Lines:	7904
Relevant Lines:	8387

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💛 - Coveralls